Does anyone really have an idea of when it's going to happen? Well... IF it happen.
Probably in the following months, definitively this year.
Bitcoin Unlimited Fork can happen anywhere between 51% and 75% if miners choose to do so.
Actually most BU miners preffer 80%. I preffered compromise in the past, but its clear there is not going to be any, so the sonner we get to 80%, the better. Even current Core miners are incentivized to join emergent consensus and finally stabilize the Bitcoin situation, because there is no future for them under Core threads to change PoW whenever they choose.
I also think so and also trading platforms will just list BTU as altcoin rather than bitcoin which may have negative impact on price of BTU as well as on support they may get afterwards. Bitcoin core will remain as bitcoin.
Maybe some exchanges, but the biggest, Coinbase made it clear they going to stop trading Bitcoin until the situation is resolved, and the winner gets Bitcoin name. I doubt they going to trade the BlockStream Core coin (or whatever it gets named) because they dont trading the losing ETC chain as well.