After having filmed the 'You are glasses' scene and being told how great she was in it, Brooke was told "they couldn't write for my character anymore." Shonda told her and to Brooke "it definitely seemed like [Shonda's] hands were tied".
For full disclosure, here's Shonda Rhimes' statement:
"Brooke Smith was obviously not fired for playing a lesbian. Clearly it's not an issue as we have a lesbian character on the show – Calliope Torres. Sara Ramirez is an incredible comedic and dramatic actress andEveryone with a pair of eyes knows that this can't possibly be true. If the magic or chemistry was off the blame definitely lies with the writers for writing Callie the way they did. How can you tell Brooke how amazing she was in her coming out speech and then say that the chemistry wouldn't sustain in the long run? Besides, they could have simply broken up and that would have made for good drama.
we wanted to be able to play up her magic. Unfortunately, we did not find that the magic and chemistry with Brooke's character would sustain in the long run. The impact of the Callie/Erica relationship will be felt and played out in a story for Callie. I believe it belittles the relationship to simply replace Erica with 'another lesbian.' If you'll remember, Cristina mourned the loss of Burke for a full season." (Emphasis mine)
What we also know is that ABC sent their stars a statement containing what they were allowed to say and I think we can call that a gag-order. Patrick Dempsey's interview on Ellen is evidence enough for me.
Here's what I think went down:
They filmed the 'You are glasses' scene and episode and I guess they have to run their episodes through with the execs. Then, three things happened.
1. The big bosses were surprise to see that this wasn't a 'Two hot girls making out while drunk' scene aka 'the ultimate male fantasy', but that this was a real lovestory between two real women, which obviously isn't hot nor interesting to the average straight viewer.
2. I hate to say that but both Brooke and Sara look more like real women than most actresses in Hollywood and I think that this was also part of the problem. While I think Brooke Smith is beautiful and amazing in her own way, the execs probably thought 'If we have lesbians they better be hot/thin/stacked/blond/young.'
3. They probably already had that idea with Erica finding out about Izzie stealing the heart and the execs probably thought that this was the best way to get rid of Erica right away. Honestly, I think that it will make some sense.
I'm still fuming and I hope that we get some more information about this, but Brooke obviously doesn't have real information either, she only knows what Shonda told her, which basically wasn't anything at all.