XM was the party that informed DirecTV of the discontinuation for it was XM's decision to drop the channels.
Another fact: all of the audio of the Worldspace channels heard on XM lives on XM's servers. XM could have continued the channels is they wanted to by taking the programming of them inside. The Worldspace channels as heard on XM were programmed specifically for XM and, with the exception of UPop, were not what was heard on Worldspace, which produced the same stations separately for the Worldspace audience.
Yes, while the audio for these channels (including sweepers, ID's, etc) was stored on XM's servers, it was Worldspace who programmed them.
All Worldspace feeds were terminated, and I believe the sats have been turned off. I think they are entering Ch 7, liquidation.
Regardless of what stage bankruptcy they are in, I feel some truth should be given here. When a company goes into bankruptcy protection, it is no longer up to them what they choose to do with the assets of the company, including company brands, programming, etc. This is left up to the court. Chapter 11 can only be filed if a planned date to exit is given. If this date is missed, then the company and creditors go back to court to ask the judge for the next step. This is typically liquidation. Once this happens, assets are auctioned off, which in this case could include brand names like UPop.
Because of this, I'm almost certain that XM was told they could no longer use the intellectual property of Worldspace, which would be the playlists, logos, and production of worldspace maintained channels.
So, while the music exists, someone from within XM would have to program it. I doubt there is interest from within XM to put money forth to do this, as they are also within inches of Ch. 11.