Do you have any references/names?
Anyway, if they did join Luther, then they would have taken the helm of this new church, not Luther. Obviously, part of Luther's dissention was dissolution of the ordained order, which makes any bishop(s) joining Luther meaningless.
After anarchy that followed, the Lutherans gathered their wits (unlike the Calvinist and Zwiglian followers) and tried to re-establish a church. But by that time everything has been broken.
Apostolic Succession and ordination is one of those, well “odd”, areas in Lutheran theology. You have to be ordained to be able to consecrate the Lords Supper, but the actual specifics of what happens in ordination, and how it happens, is a bit of an open question. One that has never really been settled.