It will be interesting to see how this plays out, and I think much of it will depend on how much of a public profile Yusuf wants to retain.
The way the likes of Farage reacted is notable. Usually when he falls out with people, Farage goes on the attack. He did the opposite this time. That's not because he is genuinely sad, it is because he doesn't want to make an enemy of Yusuf in public.
Chances are it won't have a huge impact in the short term, but if a negative light is put on Reform and people start questioning them, Farage won't hang around either. Whatever ship he has been on in the past, he tends to leave it before it starts sinking and when he has found someone else to blame.