So they did put the interim IBF on the line in the last moment after all. I didn't know that.
I honestly don't know if that would mean that Usyk is more likely to get stripped or not.
Dubois is already contracted to fight AJ in late September, so even if Usyk decided he is willing to defend his belt before the rematch with Fury, the fight won't happen anyway.
So probably the IBF will allow him to keep it, and the September fight Dubois Vs AJ will be for an interim belt. A situation when an interim champ is defending his belt against other fighters, while the original champ is not injured is a bit odd, but hey.