What did happen was about the best case. It is forgotten at times that there were still around 450 aircraft in the area ready to attack the Japanese BB's. It is also commonly forgotten that every one of the CVE had around 20 torpedoes on board, as well as a number of depth charges that could be set for shallow detonation close aboard.
Kurita suffered very heavy losses while being engaged by only Taffy Three's escorts (5 DD, 3 DE) and the aircraft of the three Taffy groups. This included the crippling or loss of four CA, with three more damaged, a CL and a DD both sunk during the engagement east of Samar, as well as noteworthy damage to three of the four BB that were engaged. In this engagement Kutita's command fired a large percentage of their AP main battery ordnance, and had most of his escort force stripped away. Any further advance would have exposed his remaining heavy units to both continued air attack, including from the untouched TF77.4.2 (Taffy Two) as well as torpedo attack from the escorting destroyers of 77.4.2 & 77.4.11.
AFTER running this second and third gauntlet, Kurita's surviving ships (how so ever many as there may have been, given the damage inflicted by Taffy Three) would have then encountered TG 77.2 with its SIX old BB, four CA, four CL, and twenty-two destroyers. While each of the Allied ships (there was an Australian CA & DD attacked to 77.2) had fired a majority of their AP ammo, the same was true of Kurita's ships IOTL BEFORE having to fight through two additional Task Groups of American vessels. Six BB with very good gun laying radar, eight cruisers and twenty two dd vs one, maybe two damaged BB without good gun laying radar, 3 damaged CA, one damaged CL, and 9 destroyers without torpedoes. Once again Kurtia's command is on the wrong side of the math problem.
Lastly, and the most often forgotten, IOTL Kurita withdrew at 12:55 hrs local time. At this time he was still several hours from contact with the beachhead forces, even if no additional combat took place (which as demonstrated above was not to be the case). At 13:30 the first strike planes from TG 38.1 appeared over the combat area with their first attack against the then rapidly withdrawing Kurita beginning at 14:00.
Kurita was never going to see the beach head.
All this aside, what happens if NO invasion of Leyte ever takes place? the IJN succeeds beyond its wildest dreams and repulses the landings. How does this change the war? Strategically, it changes not at all. Zero difference. There is a significant, tragic, increase in losses among the POW held in the Islands, this is, however, more than counterbalanced by the reduction in combat losses suffered in the more or less worthless two months of battles on Leyte.
Iwo Jima is still invaded on schedule. Okinawa is taken on Schedule. 67 Japanese cities are still burned to the ground between March and August of 1945. American submarines continue to kill anything afloat, B-29's continue to mine the Inland Sea and the sea lanes between the Home Islands. On August 6 & 9, 1945 Japan still is struck with Nuclear Weapons. With all this, does the Emperor not quail and continue the war?
If so the next seven months will see an invasion of either Luzon or Formosa and a later preparation for the invasion of Japan. During that same period of time, the USAAF is destroying a Japanese city four times a week as 8th AF resources, mostly reequipped with B-29 & B-32 bombers join the 20th AF in burning Japan to the ground. At least two, maybe three additional nuclear weapons are deployed against the Japanese civilain population before the hoarding for use during the invasion begins. Several million Japanese civilians, mostly children, starve to death while million more suffer life long disabilities from beriberi, rickets, and other illnesses related to malnutrition.