We still have people who are still on a tear about Obama's birth certificate. Hell, we still have people who talk about Vince Foster. The Rothschilds are a conspiracy theory from the go***mned 1850's that just literally never died in 170 years.
My guess as far as QAnon is concerned is that I think we'll hear less about them from the press and they might even take a hit in their recruitment strength but they'll still be as active as ever. They might even change their name, go for a rebrand - who the hell knows.