I ma on the side of look at what sales the companies in this boycott are actually making. Most of them aren't doing any LEO sales. DOD is moving away from Beretta, although that will take some time, and otherwise I don't think they are used much at all by public agencies. I have never seen an officer carrying a Beretta.
Same with most of the AR manufacturers. THey never sold anything in a government contract to begin.
Even if they boycott directly, their distributors may not and there are other ways to get around it.
There are exceptions. Magpull probably sells a lot of accessories to LEAs, and refusing service to LAPD is pretty ballsy on Barrett's part.