^I’m trying to think of which Universal IPs haven’t been used yet or aren’t currently under construction besides Secret Life of Pets (which is literally Toy Story note for note, just with pets). I can’t think of anything.
If you are talking Universal IP's...Bourne and Sing. Although they could pull an abridged card for Wicked. That said, Wicked and Sing doesn't seem to be the ones prodominently rumored.
The ones predominantly rumored is Bourne (which is a Universal IP), or 007 (Not owned by Universal, but is known universally).
Universal is weird with announcing projects. They still fear that if it's announced too early guests will put off a trip.
I still wish they just pull a Hollywood for Orlando with them going out to announce what is coming, but to not give specifics.