This change is an inevitable choice for the army to optimize and adjust.
The military academy is not a first-line combat unit, nor does it directly contact the first-line troops. To put it bluntly, it is an education and training unit, and the level of such units should not be set too high.
Judging from the effect of the military reform, the various resources of the military are actually inclined to combat units, even at the level. For example, the newly established strategic support force is directly at the theater level.
Therefore, as a non-combat unit, the demotion of military schools is reasonable.