EDIT: Sincere apologies for this, but it turns out the buzzing noise issue was simply the beginning of my monitor’s (speakers) final countdown. Just coincidentally marked by the last maintenance, and incidentally only initially triggering on Guild Wars 2. That really confused me and had me convinced it was the game client’s audio borking it up, so to speak. It’s not. At least that, phew!
So! Topic can be locked or removed. Again, my apologies for wasting time here.