Unfortunately the people that deliver these courses aren’t up to date with a lot of stuff. Much of the Powerpoint presentation was prepared years ago and hasn’t been updated to account for the raising of speed limits on A roads and dual carriageways for HGVs for instance.
I got into an argument with one of them, a retired driving instructor in his late 70s, who insisted that the speed limit on ALL UK motorways was 70 mph. Anyone who’s travelled a bit will know that there are several stretches of motorway around the UK where the limit is set at either 50 or 60 mph and is very clearly signposted as such.