I accidently reported a reply that I meant to delete.
What'll happen now, since the reply wasn't bad
Well, Fandom will review it, and then if they say it's bad, then they'll delete it.
If it is good or having no problem, Fandom will just left it
Depending on the wiki, admins or mods may interpret a self-report as a reqeust for deletion, which is fine in your case.
Just to make sure it is clear, it is not necessarily Fandom that reviews reported posts. Most reported posts are reviewed by the local admin/mod team.
What do you think?