Fair point about being asked to join the team. It tells me that the coach recognized (at a minimum) a potentially good player that fills a need. However, it's a big jump from asking how a coach envisions that a player will be used to demanding that she get a large majority of playing time.
Yeah, lots of red flags when asked to join a team. Especially mid-season.
My DD has some talent and we get asked often. It's flattering. But I've learned it does lead to a ton of questions. Some about the team, some about the coach, some about the Org, some about the other parents.
In those situations, I tend to think the grass is (almost) always greener with the team you're currently on. Plenty of exceptions, of course.