"Report established" on the ILS

I don’t know if this kind of phrase is curent in every ATC exchanges but at LSGG Geneva I always ear this phrase "

“Aircraft 123 turn left 240 cleared ILS, report (when you are) established”, and then the aircraft is established and LSGG APP send aircraft to contact Tower. This a kind of command that I think its useful so you can know when the aircraft is in the good hands of localizer for a good approach and then you can let him continue with the Tower.

Tell me your pro/cons and let’s vote,
Have a nice day, long time no posted

This is a pretty common thing to hear. This might potentially actually stop pilots from unnecessarily requesting a freq change too