It depends on how easy the lights are to break. Something in my gut tells me it'll have about the same amount of HP as Great Fox's Lasers, if not a slight bit more. So the strategy is to widdle down the hp of the lights over the course of the match (I'm almost certain Zelda can aim a Dins Fire up there) and then camp up there when it's down to about a hit or two left. Then proceed to camp until someone tries to get up, perform ledge tactics, edgeguarding, whatever and should some decide to attack the lights themselves, it'll end up crashing ontop of them anyways. It would be ESPECIALLY cruel to characters with low max jump heights like Ganon and Little Mac because it would be a struggle to get up there and stay up there. Mind you, a good player could work around the edge-games and take over the spot, but then you're faced with the other player being easily able to come back and/or destroy the lights from the distance.I really don't think it would be that easy to break the lights, if it's anything like the Luigi's Mansion stage then I don't think Zelda or any other camper would be able to break it on reaction.
Not to mention any character that decides to break the lights then loses their camp, so there is a risk to the reward.
Point is, it creates unnecessary imbalances that favour characters who can jump high.
Even if the Boxing Ring didn't have that stage hazard, and wasn't banned, odds are that tournaments would have used the FD variant of the stage, since it would be the same exact stage but without the walk-out stairs and bouncy ropes. It would be one thing if it was a Battlefield-like stage (in terms of platform placement) that was banned, but Boxing Ring is already a mostly flat stage, so not much is lost becoming a FD variant
You seem to be implying that there is an FD variant of the stage which we have no confirmation of. If I were sakurai, I would not make a FD variant of the stage. It already has 2 different appearances. It's fun and neutral enough to stay the way it is.