On the other hand, he would probably have some outdated or incompetent officers still around as well.
If there is a higher overall quality to the soviet officer corps, the question is whether or not this significantly changes the course of the winter war (bad officers hurt, but so did a lot of other things). If so, then the red army may be more successful (or less, depending on who is running things), which is where the changes start multiplying. If it procedes similarly to OTL, then events happen parallel to our history until Barbarossa.
One idle thought... If stalin isnt purging the army, then who is he going after instead?