Gotcha! Then yes, that likely was the case around opening. You're definitely right as of then.
I've noticed a very significant and consistent decrease in the SML Ops wearing Bands since mid-summer. I believe they have been enforcing that as a rule. A significant number of players on the Leaderboards were obvious TMs, which is slightly better now. Though you can still see all of the VIP Tour Guides at the very top haha.
I believe they also wanted to cut down on misinput Hard Mode gameplay. Every Key Challenge has a Hard Mode version you can unlock after beating the challenge once. Hard Mode usually involves the gameplay elements being slightly tougher, and often taking twice as long to complete.
For Goomba, Koopa, and Piranha, if the TM taps the touchpoint to begin the game on their Band it will begin in Hard Mode 90% of the time because it's very likely that the TM or the group before them won their last game.
Bob-omb and Thwomp use the Touchscreen, and from what I can tell, an NFC Field to detect all of the Bands in the gameplay area. So the TM doesn't even have to tap to activate Hard Mode. If they are in the gameplay area, which ... of course they are haha, then
every guest will
always activate Hard Mode.
Thwomp is usually hidden away enough to where it isn't too bad of an issue, but Bob-omb's queue can back up all the way to the exterior of SNW because of repeated Hard Mode gameplay. It's just an operations issue at a point. Even the Power-Up Band content isn't immune to Epic's low capacity haha.
There may be some outlier TM's that offer the Key games for non-Band owners, but it is definitely not the norm and not something to plan around. Much more commonly, they will turn guests away.
Didn't mean to come off as rude or antagonistic. Sorry if I came off that way!

Just trying to clear up how exactly the Band content is operated at this point in time cause there is a ton of confusion, and things are often changing regarding it on Universal's side too.