[WillPS]

I wonder if Sky will also be tempted to move their +1 channels to being streaming only. This would remove the need to transmit them via satellite, and the number of users affected would presumably be relatively minimal. (One might argue that there's even little or no point of these channels anymore.)

Doubt it. These are channels designed to catch casual linear viewers at little cost - makes very little sense to continue with them at all if you're excluding the customer sets most likely to be heavy linear viewers.

Far more likely they'll just continue to be gradually binned off.