This is turning very semantic, but I still think my definition is the simplest. If turning the product bad is the top priority of the rebuilding strategy and the team commits to building through the draft, they are tanking.
Whether you sit your best players, create a dysfunctional team or build a bad roster.. it doesnt matter.. its tanking if the team you put on the court is bad by design.
Rebuilding move is any move that gives away current performance for future benefit. So tanking is always rebuilding but not every rebuild prioritizes tanking.
We are definitely prioritizing evaluation (players and coach), maximizing player development and developing system/culture over tanking and have done that since early season at least. FO not sabotaging might have been promised to Hardy before he even took the job.
I personally think the best way to develop players is to make sure the situation around them is good. Even if a team tanks initially, they need to shift to creating a functional team around the prospects at some point to develop them the right way.