There seems to be a 5k drop in monthly active users (from 46k to 41k) https://lemmy.fediverse.observer/dailystats
It seems high as Lemm.ee had 1k daily active users for the last week.
Also, the "total lemmy posts per day" is about the existing total of posts at a certain date, not the posts created that specific day. Even then, 4 millions seems high for Lemm.ee, Lw has 527k: https://lemmyverse.net/?order=active
Active communities migrated a few weeks ago, so we shouldn't lose too many of them: https://lemmy.dbzer0.com/post/45977837