I find in the UK that I quite often need to request a frequency change reasonably early, otherwise I get handed over (or worse, given a freecall) just before I'm about to fly into somebody else's controlled airspace and am either desperately trying to get an airspace crossing clearance from a busy controller who didn't know about my existence until a few seconds earlier - or more likely am forced to change route and thus lose time, to stay out of CAS that I haven't permission (yet) to enter.
So, I can't say what you describe surprises me, it's UK pilots practicing what at-home would often be good practice on a long "near straight line" trip where they are asking permissions to cross CAS, rather than routing around the main bits.
G