does anyone know who would be in the next group of 5 to be up for a gp in dance if another team drops out
It's currently a group of 11 (host countries should select anyone from the next ten on the SB list at the end of last season, plus Coomes & Buckland who won a Challenger). Teams that have one GP remain on the list until they have been assigned two. If I'm not missing anyone, I think the list is the following:
Coomes & Buckland
Fournier-Beaudry & Sorenson
McNamara & Carpenter
Nazarova & Nikitin
Lorenz & Polizoakis
Popova & Mozgov
Min & Gamelin
Jakushina & Nevskiy
Mansour & Ceska
Smart & Diaz
Koch & Nuchtern
If a team has a current Challenger score that factors among these teams' scores from last season (I think Soucisse & Firus are the only other team that does), it might also be taken into consideration--though that isn't clarified in the rules.