Japanese Victory in the Pacific

Like I said, it makes zero difference. The US had four infantry divisions 1st Cav, 24th, 7th and, 96th) on Leyte ashore and off the ships by the time the Japanese arrive. In addition, the corps troops include several battalions of Sherman tanks and M 18 tank destroyers along with the usual engineers, artillery, etc. There were 80,900 men ashore before the IJN arrives.
The USN had also already landed 114,900 tons of cargo sufficent to supply these troops for 30 days. There are 37 cargo and amphibious assault ships and 90 LST involved in this landing along with well over 1000 smaller landing craft.
The Japanese had one average strength infantry division on Leyte (the 16th). Even if the Japanese landed an additional regiment and some armor it would simply have gotten ground up just like the 16th did. The US has an overwhelming amount of firepower ashore before the IJN even shows up.
Likewise, 5th AF under General Kenney was flying support missions out of airfields at a rate of about 1000 per day. By the time the IJN arrives the USAAF had fields up and running on Leyte including ones at Dulag and Tacloban.
This is all before the IJN even gets to the PI.

You might also note that USN CAP aircraft had basically shot down the bulk of Japanese land based airpower in the Philippines prior to the IJN arriving too. So, there won't be any "kamikaze" on US vessels to speak of.

 

The Sho-Go was a desperation move by the Imperial Japanese Navy in a bid to stop the American juggernaut approaching the Philippines. The Japanese knew they did not have the ships or planes to seriously challenge the USN, and that the best they could hope for was a to achieve a temporary setback to the American timetable.

They hoped to do this by disrupting the American landing at Leyte Gulf and destroying a significant portion of the invasion force before it could establish itself ashore on the island of Leyte. In order to do this, they hoped to lure the vastly superior Third Fleet away by sacrificing their carriers (which had few aircraft remaining) and attacking MacArthur's 7th. fleet with their still formidable surface fleet under Admiral Kurita.

Unfortunately for Kurita, news of the American landing force approaching Leyte did not arrive in a timely manner, so by the time he was able to get his fleet near Leyte Gulf, American forces had already been ashore for five days and had achieved all of their initial objectives. Most of the logistical ships supporting the landings had already unloaded and departed the area. The remaining tranports and supply vessels were under orders to depart on an hour's notice and would have escaped down Surigao Strait before Kurita could bring them under fire. MacArthur had sufficient supplies ashore for at least three weeks of operations. so ground operations would not have been affected.

Furthermore, MacArthur's Seventh Fleet included six old BB's which nevertheless were extremely dangerous opponents. though with limited AP ammo. It's unlikely that Kurita would have had much ammo or fuel left after destroying Taffy 3. Even if they had been able to get past MacArthur's old BB's, he would have been under strong air attack from the remaining CVE task groups and in the very restricted waters of Leyte Gulf. Kurita had virtually no chance of successfully accomplishing his mission of destroying the landing forces or of inflicting significant damage on the troops already ashore, thus the Leyte landings would not have been defeated no matter what course Kurita chose.

As far as Japanese coubnterattacks against Allied positions in the Pacific is concerned, it wasn't going to happen at this stage of the war, no matter how lucky the Japanese got at Leyte Gulf. The Third Fleet, vastly superior to the whole Japanese Navy at this point, would still have been intact. Any Japanese attempt at another Pacific offensive would founder on this one fact alone. The Japanese did not have, in late 1944, the ships, planes, logistical shipping, fuel, and other resources required to mount any sort of offensive operations in the Pacific, even in the Philippines. All Japan could do was wait for the coup de grace to be delivered by American naval and air power.

 

I agree with T.A. The most the Japanese could do was to cause a "minor" disruption to the US operation in Leyte. "Minor" in the overall scheme of things but this is not meant to disregard the suffering of those wounded in both sides.
The Japanese ships sent on that operation had very little chance of getting out, given the correlation of forces.
Okay, let's say the Japanese was able to send reinforcements to the Philippines. The most that these additional units can do is probably stay in Luzon. They won't be able to reach the Visayas area where the Americans landed. And whatever units the Japanese have in Luzon would eventually be running out of supplies.
Bottom line, the US can replace its losses. The Japanese can't.

To put this in context, go back to 1941. Remember, when the Japanese started the war against the United States, the Japanese didn't have enough merchant shipping for transporting the necessary goods, units and other necessities needed in a drawn out war. From the Japanese point of view, they figured on a "short" war and that their rapid success in the field would force the United States to ask for negotiations. When that didn't happen, the Japanese were doomed in the long run.
Going back to the Samar battle, even if the Japanese breaks through, I highly doubt if the individual transport ship captains would stay and let their ships be sunk. They would run while their remaining escorts and the other arriving US task forces run interference. So where would that leave the Japanese? They lose ships, sink a few US vessels but what do they do in the overall scheme of the US operation? Very little. As pointed out earlier, the US have already landed supplied units. Once the transports have regrouped AFTER the Japanese attack, the resupply of these units continues.
As for the Japanese units left in the Philippines, they're withering in the vine, much like what happened to the USAFFE in 1942.