Does anyone think they will?
They're going to be bottom half. Worst case, they're the MLS's Monaco: https://www.transfermarkt.com/ligue-1/besucherzahlen/wettbewerb/FR1
They'll have some star players, build a decent following distributed among the Caribbean, but I'm definitely not anticipating a large local fervor for the club.
Miami / South Florida has to be one of the worst fan bases in the entire country. It doesn't help that a huge part of that population came from somewhere else in the US. If I retire and move from NY to FL it's not like I'm going to become a Marlins/Heat/Dolphins fan. I'm still going to follow my NY teams.