I'd have to wonder how hard it would be to get tickets to begin with. So this is from a few weeks ago and I haven't heard anything about changes but 13,000 fans doesn't leave a lot of wiggle room for Bills fans. I'm sure some will attend but my guess is 20% of the 13K at best.
https://www.thephinsider.com/2020/8/24/21398937/miami-dolphins-2020-season-stadium-fans-covid-19-coornavirus-20-percent