Is the current trend of promotional melee good or bad for boxing?

Schedule snatching.

Well, TR has done it with before with other promoters, GBP did it with TMT. I'm sure TMT will eventually do it if they want to assert themselves as a force.

So, do you think this benefits the sport or not?

I can only think of the negative so far. For one, with multiple cards on at the same time, especially if most or all are on PPV, not all the fans can afford all of the cards available. Too many fights on one night from different networks is not bad, if it's free.