[Brekkie]

Because it makes no commercial sense……
Is there a queue of channels wanting carriage on the platform?
Going T2 AVC AAC. Is about 15 SD channels more per mux …
And if the government intervenes to do the Vaizey plan say 12  years too late,
that frees a very expensive PSB mux …..
with no income for the remaining half of it contract ….

And linear viewing is reducing ….. so the number of channels will decline.

You'd look for some channels to go HD though - roughly speaking you can have 4 HD + 12 SD channels on a mux to replace the DVB-T SD muxes, and 6 HD + 6 SD on a PSB mux.    


However you look at it Freeview has completely screwed up when it comes to HD and the longer it goes on the less likely they can fix the issue.