Strong paranoia and scaremongering.
I mean, you gotta do whatever helps you sleep at night but are we really buying into the idea that muscle is that fickle and tenuous?
As long as you dont jump suddenly into a 1000kcal deficit, you wont lose any more muscle now than you would waiting another 4, 8, 12, or 85898 weeks. And, whilst MrParanoid is waiting out biding his time for his gainz to "become more permanent" (lol, muscle isnt concrete), youve already completed a mini cut and are reaping the rebound growth benefits of having transitioned back to a bulk.
If he is currently in a bulk or kcal surplus, cutting calories, reasonably, wont suddenly put him in a deficit. He'll move gradually from a bulk, to less of a bulk, to maintanence, to deficit. Over weeks.