That seems like an odd move. If you have gone the 'old' route to CPL you will have at least 250 hours when you qualify for the advanced course, if you have gone the integrated 150 hour course you probably won't.
So requiring guys to have 250 hours total doesn't mean they are necessarily getting people with any more experience than a fresh CPL. It means if you've done a 150 hour course you will need to go (work to) build hours but if you have a 250 hour CPL you won't. 250PIC or 400TT would be a better hour threshold if they wanted to avoid CPLs straight from flight school.