After the 2024.4.1 patch, I've noticed that the VRCPlayerApi variable inside Udon scripts will automatically replace itself with another player (or the instance owner/local player) if the player it was set to leaves the world.
I am unsure if this was an intended change, but I am fairly certain that worlds scripting that relied on knowing if the variable is equals to the player that left now no longer behave as intended after this patch since it always switches to players that are still present.