The scale of repressions are usually miscalculated and especially for officers. There are popular opinions, like, the "Purge killed all officers" or something like that but simple answers for such a complex phenomenon are rarely correct and are easy to manipulate in favor of whatever political agenda you have, both pro and contra.
In 1937 11034 (8% of all officer corps) officers have been "Purged", in 1938 - 4523(2.5%) - and it is a common manipulation when someone states that they were all killed, which is wrong. Some were shot, mostly generals and Old Guards, some were imprisoned, and some forcibly retired.
For one, the Purge opened the way to young and promising officers, like Zhukov, Konev, Vasilevsky etc. and many others saw this as an opportunity, often accusing their commanders to get a promotion.
It is eternal debate with numerous arguments from both sides of discussion whether the Purge was harmful or beneficial to the command staff and its effect on WWII, but it was not a source of, like, widespread civil war-like uprising in a population, more of a coup of officers and power blocks, fearing they will be purged next.
The biggest impact Purge had, in terms of officers, is promoting indecisiveness, when officers hesitated to take bold actions in fear that they will fall victim to some accusations and would be purged or punished should their actions fail. the indecisiveness was the plague of USSR command cadre with only the most brave and capable commanders being able to overcome it. And this is not represented in HoIIV Purge effects at all, I suppose because devs never bothered with Purge researches or SOV never being their target for DLC.