All fair enough, but I’m increasingly of the opinion that signage at T2 arrivals should warn you of this if you choose to make an airside transfer. I’m a reasonably experienced traveller, first flight taken in 1970, but I wasn’t expecting what happened and I was concerned I’d (somehow) gone wrong.
BTW I reckon BE’s move of their NQY service to Heathrow will see a jump in numbers doing the transfer; it gives a several times a day connecting opportunity for getting to/from Cornwall (back to the old Brymon days but sadly without Plymouth
).