I have a question about new user accounts as logged on https://christipedia.miraheze.org/wiki/Speciaal:Logboeken/newusers . Are they users that want to edit the wiki Christipedia.miraheze.org, or are they users that want to edit all Miraheze accounts / want to be members of all wiki's at Miraheze? On our wiki Christipedia they cannot edit without membership of the user group Editors (= Redacteur), which wil be granted only after a an intake. So I am curious about those strange user accounts.
User accounts are shared across Miraheze system. So if you have account in christipedia.miraheze.org, you can log in with that account / Password in meta.miraheze.org. If your wiki requires users to have specific permissions (i.e. members, editors, ...), you will need to grant those user rights before they can edit.
But remember - user accounts are not automatically created when they sign up on other wikis: you have to explicitly click your link and let the MediaWiki auto-login to complete. (You may have to visit Login page to make this work.)
From your comments I conclude that the user accounts mentioned on https://christipedia.miraheze.org/wiki/Speciaal:Logboeken/newusers are made specifically on the wiki Christipedia (not on another wiki), but can be used on other wiki's as well if they have been granted the right permission there. Is my conclusion correct? In that case it is strange that several accounts are made on Christipedia without any following request to grant a right to edit pages.