Board Thread:Questions and Answers/@comment-9826910-20130618064245/@comment-11051098-20130718050202

It seems unlikely, yes. But we know nothing about how the medallions work. We don't know how the medallion holds the power of the Bankai.

Yhwach said to Yamamoto that it was not like they couldn't steal his Bankai, it's power was just too enormous for someone other than him to handle. So it seems the medallion can hold even the strongest Bankai with no problem, but the one wielding it has to be powerful enough to handle the power.