Last year, Highland Park Frisco went to FW, both are Dallas schools; also Lake Travis/Westlake went to FW, both Austin schools. Maybe Brock/Argyle a while back (guessing, haven't checked.) So it does happen, seemingly maybe couple of times/year.
My understanding - and this is from a conversation I have had with a longtime DAL member last year, or year before:
"Fort Worth had that conversation with Brock after they chose another chapter in the playoffs. They actually told them to go find another chapter to cover them. Brock complained to TASO. TASO somehow forced Fort Worth into covering them after they told them they wouldn’t."
My issue with this, is that we are independent contractors. TASO shouldn't - rather, can't - tell us we HAVE to cover a certain school. The only way I see for a chapter to be able to do this successfully (if TASO is going to advocate for coaches and schools, not officials) is for chapter members to block the school. 'Sorry coach, can't cover your games, the majority of the chapter decided to block you.'
This falls right in line with the quiet rule change they were implementing (can't work a semi, then a final) that coaches complained about, and they (TASO) quietly decided to not implement the rule.