Yes this is the new BA arrivals plan now I’m afraid whilst CTA has been closed, according to ground staff I chatted to when I had the same issue on my recent flight. It’s a complete lottery as to when you arrive/land, but if another flight arrives just before you, then unlucky you’ll be sat on the bus 45+ mins whilst they wait for the previous flight to be totally cleared and emptied and security searched from the domestic arrivals area with all their baggage, before they allow your flight to even be let into the doors of the terminal.

Premium indeed, hope nobody is in a hurry or values their time …