I have been a member of a snapshot server which updates to the next available snapshot immediately. 
In the version 21w38a I have still met pillagers but in 21w39...

No illagers. No PIllagers, vindicator, Illusioners.
They do not spawn in mansions and outposts. Since the server is on this version I have not seen patrols either.  I also went into singleplayer to try replicate it. 
So here it is.
No illagers spawn:
Steps to repliacate:
1. Creata world in Mincraft Jave edition: 21w29a
2. Find a Outpost or mansion 
3, Try looking for illagers