[i.h]

That's going to be the same situation as yesterday. Analogue to digital was a massive significant shift and something the general viewing public can understand and embrace. A change in modulation standards isn't.

If a whole platform is switched off, like terrestrial or satellite then that will be worth marking

Not quite. If you use Freeview, you are more likely to see/use the SD channels since they appear first in the TV guide (Freeview Play / CLM excepted) even if you have an HD TV. You may also be using an older TV that can accept HD but is not DVB-T2 capable, which is presumably why there's no real appetite to switch despite the obvious efficiency gains.

Yesterday was a much more niche event because you would have needed to still use a Sky SD box (which have all either died from old age or are so unusably slow, it would be surprising if anyone still did) or one of the handful of Freesat SD boxes that quickly disappeared from sale.

Not that I am suggesting some big Northern Ireland style send-off here!