will chess ever die out once its fully solved?

You realize that Thanksgiving is a US-only thing, right? This means that 95% of the world population doesn't celebrate it. Half of those have never heard of it, and the other half have only a very vague understanding of what that might be. ("Something about the independence of the USA, right?")

A bigger threat to the game of Chess than a complete solution is AI finding systems which must be remembered by elite players in order for them to avoid defeat against those who have committed them to memory. It's the next logical step from the enormous amount of analysis which the top players go through in order to train for tournaments.

I think no, technically chess can die if humanity will roll back in progress or if it goes extinct¯⁠\⁠_⁠(⁠ツ⁠)⁠_⁠/⁠¯

By "solved" they tend to mean the entire web of moves and counter-moves being assessed. You will know that we had long discussions about that and there was a fundamental disagreement, where you were following the recommendations of a GM who was thought to be discredited by others; so that you thought, at the time, that a full solution, or a kind of exposition of all the possible permutations of moves starting from the starting position, is possible. Others, including myself, had calculated that at present computing speeds, such an enterprise couldn't be completed in millions of years. We tended to think that although it's natural to invent shortcuts for any analytical process, the ones recommended by this particular GM, who was not a computing expert, were unrealistic and incorrect. We know inductively that chess is a draw from the beginning position, given best play by both sides.

I say that we "know" but naturally, there's no formal proof, which is impossible: therefore we go with the next best procedure, which is by inductive assessment. The same procedure by which means we assume that the sun will rise tomorrow or that if we release a heavy weight, it will tend to accelerate towards the nearest significant centre of mass, i.e. my big toe.

listen up nobody dies everyone is safe fools lol

Thanksgiving, or in some countries Thanksgiving Day, is celebrated in about a dozen countries throughout the world. Always in the summer or fall, and usually to recognize harvest season although in some countries it's to celebrate other reasons to give thanks.