On an FGW HST though its always in the same place unless something is wrong, in which case you'd probably still get an announcement.
There's a sufficient amount of HSTs reverse-formed to make it an issue, I think.
What annoys me is the amount of announcements at Luton Airport PW about not using the escalators if you have luggage. What's special about the escalators at Luton Airport PW? Just about every other station is happy for you to use theirs.