would an AFI work, if you had a back up power (5kw generator) feeding the breaker?

The breaker would be fed through a manual transfer switch, one side of the switch from
the AFI and the other from the generator.

It seems like the breaker would be an intergal part of the neutral since the banch circuit is landed in it and then bonded to the nutral busbar. And if the breaker is de-energized would it be an open circuit when the generator tries to feed it?

Any thoughts would be appreciated.
Thanks.