He's going to play for Inter Miami. Although he's 36 now and not nearly the same player as he was at Barcelona, his presence definitely will attract large crowds.
I know that it's impossible because of the winter weather in North America, but if the MLS played at the same time as the major European leagues, it probably could attract more players like Messi in their prime, which would make the MLS, which has come a long way from when it first started, an even better league. Unfortunately, you just can't play soccer in the winter in many of the MLS cities.Resale ticket prices for many Miami games already up to $400+ each.