No, you should not have to have a MB "reset". The MB does not contain any information whatsoever. It is merely a device for accessing your
MDE account, which is where all the data about you and your trip(s) is stored. All bands on your account are interchangeable and all will work for all trips.
That said: each resort is managed independently, and the resort system allows each one to do slightly different things, including limiting the number of bands that can be used for resort- specific functions. Yacht and Beach Club do this often, as a way to prevent non-guests from accessing SAB by using extra bands from friends who are staying there.
Because of this resort specific functionality, it is possible that you could have an issue at the second resort with your band not opening your door. In that case, the front desk will force the system to override the block out that the first resort placed on your account and allow the band to be used. Not a reset of the band - it's a clearing of your MDE. CMs generally don't really understand the workings of the systems and the technology, so I can understand someone saying they're "resetting your band", but that's not what's happening.
Again, you shouldn't have a problem, but it's always possible.
Steve