I don't know where people started getting the idea that shedding players who don't live up to their contract value or don't fit the longer-term vision of the team or are duplicates of existing skillsets = tanking. It's not tanking, it's attempting to get better using the assets you have on hand. It's what every single team does every single year in every single sport -- or else the GM isn't doing their job. The only difference from team to team is the scope of change on an annual basis, coupled with your window for success, which will dictate how hard and fast you approach the changes to your roster.
You have to look at it from Ujiri's perspective: if you don't believe that the pieces you have are the pieces you need to eventually win a championship, then it logically follows that you will change some of those pieces. Which could lead to losing more games, or winning more. That's the approach I believe he's taking -- opportunistic, ready to move assets at a moment's notice if the return is in line with the kind of roster he sees eventually winning a championship.
I don't think he's currently looking to make massive changes, but I don't think he'll turn his nose up at a big move if one comes his way, even if it means less wins in 2013-14.