Looking at what happened after bitcoin cash was done. Btc crashed hard and alts mooned.
I think later this week we will see exactly the same thing.
Bitcoin gold is by far not the same thing as bitcoin cash. Bitcoin cahs had a lot of influential people backing it, while bitcoin gold is really just sort of a project for money for the devs. There is much less hype this time round at least in my opinion.
Sure, altcoins could go up, but it's not going to be the biggest rally.
Plus after BCC, bitcoin actually went up quite a bit.