Yep they are absolutely going to use the BFA client.
No older client will work with the non gameplay backend things, security etc.
Classic, they only had the last rendition so options were about 0
TBC i do not know what they have, so can not speculate.
If they had a full archive, perhaps they could use the last content completion patch which i think is a little bit before the last version patch.
Dodging some nerfs would be nice, but like i said, i have no idea what they have archived.
I wouldn’t call classic lazy, simply not feasible to hand recreate what you do not have, costs too much.
And i dont think neither you nor i would have been terribly interested in buying another copy of a game we both have sitting on the shelf?