This info belongs mostly in the rumor category but I'm posting it because I'm giving it some credibility as I'll explain.
First - what I know to be true. There's a big ugly dude back in the Komodo dragon habitat but he's on loan from somewhere in Miami so he's a short timer. Disney has, however, acquired three more and once they've cleared quarantine, an adult female will be going in. The other two are juveniles and of a size that they could conceivably climb a tree and escape and then take up residence at Blizzard Beach or on 192 somewhere so they will go into a habitat at Rafiki's for some period of time. Presumably they won't be part of the petting zoo.
This following is strictly rumor from a CM but I'm willing to give some props to her credibility because while she's newish somewhat, she had gone well above and beyond learning as much as she could about the animals of Asia, their habitats, and what their treatment and routines are at Disney. Also, she made it very clear during our long conversation when she was saying something she knew to be fact and when it was just something she had heard.
As most people know, two of the original six tigers have died in the last couple of years and the remaining four are 16 years old and older so their time remaining probably won't be more than four to six years. They were all mixed breeds rescued from a Texas ranch and were going to be put down until WDW got permission from the AZA to take them in with the provision that they never be bred.
AK is in the process of acquiring three new tigers - two males and one female - who are purebreds. The CM had heard that they are Bengals but she didn't know for sure. She had also been told the female is on property but again not sure. Once they finish a several months get acquainted period, these newcomers will take over one of the habitats, never to mingle with the existing cats.
And if she's correct, AK aims to begin a robust breeding program, so in a year or two, we might be treated to seeing tiger cubs on the Trek. Also, we might be treated to a lively brand new tiger "behavior" that we haven't heretofore seen.
Take it all for what it is at this point, a rumor. But my fingers are crossed.