I am using the Curseforge app. Created a new profile for MC 1.18 using Forge 38.0.15. No mods installed.
Pillagers do not seem to be spawning at pillager outposts in this version of Forge. Tried the same world seeds in 1.18 vanilla and pillagers were spawning at outposts.
Example:
World seed: 7049875907157468887
Pillager outpost: -169, 84, 729