Just my opinion, but I would think that trying to make it as a new martial arts studio - especially BJJ - right now would be about the worst career move you can make.
BJJ has become more mainstream but its still a tough sell to newcomers. Even if COVID-19 died out tomorrow, lot of folks will have second thoughts about swapping sweat and air with strangers. The hardcore practitioners will come back, but folks that might have tried it before and gotten hooked on it now won't take the introductory lesson. The TMAs, to a lesser extent, will have the same problem.
I can imagine a lot of martial arts gyms will close.