According to a new report from Radar Online, it may be a feud between Dianna and Lea Michele that caused her to be excluded from the special episode.
Dianna, of course, has been such a big part of Glee, playing Quinn Fabray, who dated Cory's character Finn Hudson, after all.
An inside source tells Radar Online: "It's shocking, because even though she's not contracted for this season, many other actors returned to pay tribute to Cory...even ones with less of a story connection to Finn than Dianna had!"
The source added, "Remember, she played his GIRLFRIEND on the series, and was a major part of his storyline."
The insider squealed that Lea and series creator Ryan Murphy "intensely dislike Dianna and have both worked to marginalize her as much as possible. They never saw her as a team player."
Further, the source added, "They simply did not want her sharing the glory for this very special episode."
We're not sure we're believing this--if memory serves correctly, weren't Lea and Dianna roommates and very close friends?
Ryan recently noted that those cast members who wanted to be in the episode contacted him--so did Dianna not want to do it?
In an interview with the New York Post, she seemed surprised not to be asked back for the tribute.
At the time, she said, "I think moving on might be the wrong choice of words because [Glee] is always going to be a part of me and with me and I would always go back."
We'll definitely be missing Dianna in the episode.
UPDATE: E! Online reports that there's no truth to Radar Online's story about Dianna, with a source who works on the series telling E!, "She is still very much a part of the Glee family and always welcome."
Another source says the buzz about a fight between Dianna and anyone involved with Glee is "not true at all."
The reason Dianna (and Heather Morris, for that matter) won't be on Glee? Turns out it was a scheduling conflict, with a source explaining, "We included everyone we possibly could given schedules."
Gallery | Cory and Lea: A Romance Remembered