I don’t think video posting order will be the performance order. They need to show Grace as the Blake’s last rehearsal. Pretty sure Blake is gonna say you’re my last rehearsal to Grace. At least TB’s last performance should be Grace unless TPTB manipulate it.
in this interview around 2:36 he said he’s most probably not coming back as a mentor.
He equivalent it to a coming back to a prom with a junior gf after graduating Highschool.