TooDarnHot, Cry-Baby performed that at the MTC Gala, so I think it's fair to expect they will do it at the Tony's too. Having not seen the show and having only read the reviews, it did make the show seem fun and high energy so it's a good choice for them.
The Lion King thing makes sense since Whoopie was a voice in the movie, and honestly, the new musical performances medley they did at the Gala were on the whole not terribly exciting when taken all together. Not to say it wasn't good, but Cry-Baby was the closest to electrifying of the shows that did perform, and based on that alone I can understand wanting to put in some old crowd-pleasing numbers for ratings purposes...
"I thought that that was just going to be a like one shot deal for me, you know, but they kept talking about it like, 'when we do the production, when we do the production', and I was like, 'yes, yes, when you do the production, cool, I will come and see it'". - John Gallagher Jr. on SA