To answer the question presented here, rather than the specific scenario (which seems to have been amended).
The general approach to questioning a migration is to open a Meta question on the topic. Basically, provide a link to the question that was migrated, explain why you don't think it should have been migrated, and the ensuing discussion will help determine whether the migration was wrong and should be undone, or if it was correct.
You can comment on closed questions, and that is generally the primary method for opposing closures (unless the particular topic is big enough to warrant a Meta post). However, in the case of migration, the question becomes locked in addition to closed, and this does prevent commenting. It's still reversible - a moderator can clear the migration history and unlock the question. Which, to that point, if consensus shows that the question should be reopened, but a moderator hasn't been a part of the exchange, don't be afraid to flag for moderator attention in order to ping someone who can fix the issue.