The last we see of Sai Sircu, she exploded inside the warship Devastation. But it was never officially said that she was dead, and there are characters like Darth Maul who survived horrific deaths.
As of 2023, no sources have stated or implied that she survived exploding. In the cutscene from the game itself, she appears to explode into energy and tiny fragments:
The official strategy guide to the game describes her demise as final:
Once she's sustained too much damage, Sai Sircu backs away and falls to her knees. The energy beam surrounds her and slowly lifts her into the air. The Force energy flows from her to the four surrounding crystals and quickly amplifies!
Suddenly, in a beam of light, Sai Sircu is joined with the Force... permanently.
(Star Wars: The Clone Wars: Jedi Alliance Prima Official Game Guide, page 59, via Internet Archive)
The only reference to her since then is a 2010 article in Star Wars Insider #122 about the Nightsisters, which only describes her role in the game:
In conjunction with The Clone Wars movie and TV series in 2008, LucasArts released Star Wars The Clone Wars: Jedi Alliance for the Nintendo DS focusing on a story that pits the Jedi against Nightsisters, led by Sai Sircu and Yansu Grjak, who ally themselves with Count Dooku. Ros Lai from "Infinity's End" appears in the game; her look was heavily influenced by the "Sith witch" concept art from The Phantom Menace.
(Star Wars Insider #122, "Everything You Always Wanted To Know About The Nightsisters But Were Afraid To Ask", via Internet Archive)
Since she only appeared in a single Legends work that hasn't been recanonized, it's very unlikely that future works will revisit or retcon her death.