When tours close...

I wouldn't assume the rules for Broadway and equity tours are "the same", but, yes, there is some notice requirement and equity members have to be returned to their city of origin.

This was a prime motivation in the founding of Actors Equity a century ago: producers commonly blew through their grosses and then left actors stranded wherever they were when the money ran out. (The first scene of ON THE TWENTIETH CENTURY deals with this in a comic way.) The last I heard, producers of equity tours had to put up bonds with AEA to cover severance and transportation for actors when the tour closes.