I don't think it's a done deal that Toronto is getting an NFL team. I don't see it happening.
Secondly, the Jays aren't top of mind because they haven't made themselves to be top of mind. When the team wins, historically, the crowd shows up. However, they haven't done that. There are alot of baseball fans here who refuse to pay money for a sub par product. I'd argue Jays fans are the smartest fans in this area to be honest.
So, no, I'm not worried about the Raps future. The Raps have a die hard fanbase here, it may be a niche market, yet it supports it well. Also, it has the backing of MLSE.