Many barrels measuring ~14.5" do have the muzzle device pinned/welded (some do not, but often the more reputable manufacturers will). I'm not aware of S&W's tendencies. Rarely will a 16" barrel have a fixed muzzle brake. I might be wrong, but it appears yours is a 16".
If you have any interest in .30-cal rifles (especially 300blk, and even 308), it could benefit you to investigate a 7.62 suppressor. That's the next one I'll buy. They may be a bit more expensive than a .224 suppressor, but they'll generally perform equally well with a 5.56 or .30-cal rifle. And 300blk's performance lends itself to suppression far better than 5.56. If you're gonna pay a buncha money only to wait 10 months, you may as well come away with the most versatile setup possible...at least that's my thinking.