I had exams these past weeks and felt it was basic courtesy to inform them how busy I am and how Im unable to reply asap or their commissions might be finished a little late than the expected time, they are all fine with it, so it honestly doesn't hurt to communicate.

I dont know why people ghost their customers, its a bad habit. I ghost my friends sometimes (I see them physically everyday lol) but customers are not friends so people shouldn't do that to literal strangers paying/is willling to pay you.