Ed Boon has very unsubtly hinted that the next character that's revealed for Mortal Kombat 1 will be from the 3D era, which supports earlier rumours that Ashrah is next in line for the roster.
Later today, Ed Boon and several voice actors working on Mortal Kombat 1 will be taking part in an hour-long panel at San Diego Comic-Con to reveal more details on the game, including announcing at least one new character who's going to be joining the roster as well as having three separate trailers to show off.
Over the past few days, Ed Boon has, as you'd expect, been teasing fans with what's going to get shown off at San Diego Comic-Con and dropped a few unsubtle hints that give us an idea of what's coming up. Yesterday, Boon tweeted, "Trailer hint numero uno" along with a gif of someone in 3D glasses, clearly hinting that the next character (or characters) that's going to be revealed is from the 3D era.
Although that might not seem like it narrows things down at all considering how many characters were introduced in the 3D era of Mortal Kombat, there's one that's been rumoured heavily above the rest. Ashrah, who debuted in Mortal Kombat Deception, is not only one of the most popular characters from that era, but there's also some decent evidence that suggests that she could be the next character revealed.
In the description for the San Diego Comic-Con panel, it mentions that Kelly Hu is going to be part of the showcase "as a character to be revealed at the panel". Hu has voiced several Mortal Kombat characters in the past, but she's set to voice Ashrah in the Mortal Kombat Legends: Cage Match movie, which makes it likely that she'll return to voice the character in Mortal Kombat 1. With that in mind, it seems incredibly likely that it'll be her who gets revealed, especially with Boon's tweet about the 3D era.
The next hint that Boon dropped was a tweet that said, "Mortal Kombat ain't just a video game". Considering Boon mentioned that there were going to be some surprises at the show, it's possible that we get to see a look at the upcoming animated movie, or even some content that ties into Mortal Kombat 2. However, since the SAG-AFTRA strikes are still ongoing, this could be something that doesn't end up happening in the end.