They haven't been silent. They've repeatedly said that they would like to add more DLC but have no plans at the moment.
Or they could say nothing. But hmxhenry has commented as recently as a few weeks ago.
I think the refuse to deny Beatles DLC simply because of how profitable it was. They want to keep it as a viable open option for if they decide to, seeing as this was some time ago, who knows besides the executives down at HMX.
Pink Floyd Wishlist : http://www.rockband.com/forums/showthread.php?t=196856
I just want to be able to export Beatles: Rockband.
This game has been available for almost 3 years now.
We should be able to export it!!
Weren't they've planning to make the keyboard in this game? XD What happen to that plan? ( I've Heard it in a Game Informer magazine )