Accacin parent
I've already heard stories of people coming back to the UK from a trip abroad, and UK border staff insisted to see their BRP even though it's acceptable now for it to be digital. I'm assuming it's going to be a right pain in the arse for my wife when she comes back to the UK from visiting family abroad.
I recommend printing some documentation from the government website wherever it says that $x is allowed or $y is deprecated. It won't stop some officious c*nt at the border, but when they call their supervisor, the latter might be able to recognise enough of the words to look it up and figure it out.
The article states that the change is due later. I know someone who received a BRP just days ago and was told that the electronic visa system isn't yet available. So the BRP has always been and remains mandatory for travel, until these changes take effect.
As far as I know they are live. People are using the share codes for renting, etc. On /r/ukvisa I've seen a few stories already.