That I have never had happen and would be very disappointed by that unless it was for safety reasons (turbulence or something that prevented the FA's from moving earlier).

I have not noticed this with sUA or sCO FA's as a group. Now that is not saying much since I am not the most observant person in the world. Individually I have very attentive FA's and very what appears to be lazy FA's. Very inconsistent service. Sometimes a Pre Departure Drink and sometime not.