[Keith]

Are they not keeping one legacy nationwide SD stream in the short term at least?

Looking back I believe the 'nightlight' SD service for satellite will close on in March 2024.

I guess the outcome of WRC-23 later this year in Nov/Dec will affect what happens with Freeview. I gather this is why the BBC have yet to renew the 'BBC B' / PSB3 multiplex, which currently expires in 2026.

Speculating, but possibly if the (remaining) Freeview spectrum isn't protected at WRC-23 the BBC might look to implement a nightlight service on it's SD channels within the next couple years, so that PSB1 could then be converted to DVB-T2 and the BBC move its HD channels onto that multiplex and allowing someone else to take over PSB3.

I dare say a nightlight SD service might been implemented on Freeview in the not too distant future. With PSB3 having recently been upgraded to support English regions it would arguably make sense when PSB1 is eventually upgraded to DVB-T2 for it to only support variations in the nations. For that reason I could imagine BBC One remaining on PSB3, regardless of whether the BBC owned that multiplex.