Microsoft has announced that wiki’s will be retired from Teams in June 2023. Any data stored in wikis must be migrated to OneNote.
How this affects you:
With this release, users have an option to export their wiki content to OneNote notebooks in Teams standard channel. After exporting users can go to the Notes tab to collaborate using OneNote in channels.
Note: Users can continue to access and edit existing wikis but can’t create new wikis in Teams channels.