It's not a written rule Sugah, but lots of people find it a great help.
over here, I find that people who have been to rehab do that, and it sure seems to help them!
I did not go to a detox or Rehab ( never knew they existed til I got in the rooms) lol, but I did a huge number of meetings anyway, cos I grew to love thwem, still do
IMO the more meetings the better in early sobriety
HUGX
Lee