I agree, that when possible, such details should be included. If someone sends proof with their consignment, regarding who did the work, or if the auction house sent the work off, the item's description should include that info., IMO. It would also be good to have before/after photos, showing what work was done, etc.
Different people have different methods, and results are sometimes significantly different. Of course, some folks would pay more for something that was restored by a specific company, and some folks would pay less, or not even bid on something that was restored by a specific company.
I'm sure there are buyers who are skeptical to purchase something that has already been backed, as it could be like buying a wrecked car, that had shoddy work done to it from an infamous shop, and/or possibly "smoke and mirrors" to conceal some things.
Also, as you said, with the history of the piece. It's always nice to know as much as possible about something, especially when buying it.