First off, I'm not the one purposing a "Fork" but you definitely have valid points of intellect, thankfully someone does...

Rollback pre-London would obviously be the optimal Forking scenario, for all of these reasons. However ETC would then be a direct competitive consensus network and a Fork wouldn't make sense necessarily. So they'll need new updates and better scalability protocols to really further a PoW Forking successfully.

PoS absolutely favors Centralized Control, and especially favors institutianal Control by its mere operative principles. It starts to make Crypto resemble nothing but a Tech Company Governance by a few Institutianal Holders & Whales who can control & manipulate the project.

The purposed Forking reasons are fairly obvious there's a HUGE Trillion Dollar PoW network, which honestly is up for grabs post merge, as nothing else can handle the Hash and produce any reasonable returns. Also much of Eths valuation was due to this huge network of supporting infrastructure. Therefore it's a wildly smart move for someone to move into the PoW chain and continue operating it and take from ETH Eco System those who wish to stay on true Crypto PoW Consensus.