The fate of the MMO's versions of Romulus and Remus was determined by the 2009 Star Trek film.
Tomorrow, Star Trek Online will get its first major expansion since the MMO launched in 2010. Legacy of Romulus adds the Romulan Republic as a playable faction, and a WarCry interview with producer Daniel Stahl revealed the impact that J.J. Abrams' polarizing film reboot had on the game. According to Stahl, because Romulus and Remus were destroyed in 2009's Star Trek, "we simply had no choice but to keep the planets destroyed in our game."
Of course, that doesn't apply for every plot point in Star Trek and Star Trek: Into Darkness; only changes to the Prime timeline will appear in Star Trek Online. As Stahl points out, "Vulcan still exists in our game and in the Prime timeline even though it was destroyed in the Star Trek reboot timeline."
The destruction of Romulus in the Prime timeline was a pretty big part of the 2009 movie, and it's interesting to see how those story choices are being integrated into Star Trek Online. "Romulans have a much more personal story and their missions and gameplay reflect the challenge they face to survive in a hostile galaxy," Stahl said of the expansion's gameplay. "Creating a Romulan and playing through their first episodes is a vastly improved experience than what it was like creating a Federation captain back at launch."
Legacy of Romulus is set to launch tomorrow, May 21. For more on Star Trek Online's first expansion, check out the full interview.