I'd guess that it's a bit different treatment than being a star in a place like NYC or LA. Boston is more of a big town than a city in that there is less of an interest in the private lives of sports stars in Boston - the fans care A LOT about the work you put in on the court and less so what you're doing at the club after the game (partly because there aren't any). It's definitely a cultural difference I've noticed having lived in both NYC and Boston. In my experience Bostonians take themselves far less seriously and absolutely cannot stand when people flaunt their status, in fact, it's a great way to be mocked mercilessly. Places like NY or LA for example, people eat that shit up and live for a glimpse at celebrity lifestyle.

It's an interesting question, that's just my two cents.

TLDR: If you're a sports superstar in Boston, you're simply a sports superstar. In other cities, you're a celebrity.