I don't understand requiring a transaction ID to migrate. Is that really a necessity? I almost certainly don't have the transaction ID (I haven't yet tried to

I don't understand requiring a transaction ID to migrate. Is that really a necessity? I almost certainly don't have the transaction ID (I haven't yet tried to migrate), but I also certainly do not expect that they can require that I supply for a successful migration. Requiring this is akin to stealing something I bought. Are people okay with Microsoft stealing from them? I'm certainly not. This sounds like fruitful ground for a class action suit, if true.