if this fork is anything like the last one (bitcoin cash) then bitcoin price will rise after the fork. people were also speculating price fall, split, death,... about bitcoin before BCH fork too. but we saw a gigantic rise afterwards.
and also we have an additional good news about CME opening up future investments for bitcoin and it seems like the market is taking it seriously. and that is bringing in a lot of fresh money. the other day i read a large number of users have signed up on Coinbase (1 million in a day or something like that). that shows there is a new rally on the way. specially when this fork is out of the way.
i said all that to say when bitcoin rises, we have seen multiple times that altcoins get dumped hard. in which case i wouldn't expect any ATH from any of them.
Logical conclusion, but what if this fork namely B2X becomes the winner, because I read the words of verified twitter profiler, that the btc hashrate could drop 85%.
It won't drop by 85%. It will drop a bit for a short time
if B2X will be significantly more profitable to mine but that won't last long, not even with very deep pockets bleeding money into B2X.
Same thing happened with BCH:
https://fork.lol/pow/hashrate (not sure how reliably this is).