I'm not so sure the WSJ is the best source of info on this. Yes, trading land in Donetsk isn't ultimately a good thing, nor is the appearance of a retreat, however, if you read between the lines there are a lot of potential advantages here.
Pulling the Russians forward and out of entrenched positions actually makes them more vulnerable than before. It stretches their already piss poor logistics. Plus rather than being in concrete bunkers, they find themselves sitting in desolate fields, which by the way they destroyed with their artillery (no cover). In this war, if you find yourself standing in an open field, there is a good chance you have but minutes to live. Plus, the ground they are trading quite frankly is destroyed and mined. There is a great chance the Russians will blow themselves up with their own minefields.
Yes they are trading ground, but it's being done in a tactical manner. To put it in football terms, you are actively encouraging the Russians to out kick their own coverage. It should come as no surprise the WSJ found a military member willing to question the strategy, however, one must also concede that there is a good chance this is subterfuge.