Here is the story.
Yesterday one post i made maybe 1week ago got deleted by facebook for nudity (there wasn't nudity on that video).
When trying to login they notified me that they deleted that post.
They were 3 admin on that page, 2 accounts were mine and the other was for a friend which I used as backup in case I lose all my accounts.
So when he tried to login he also received that notification from fb and he asked me to remove him from my page so I did it.
Approximately 1-2 hours later after checking new posts here on blackhat I tried to login on my fb profile and there were the photo verification.
I was tired so I did nothing until this morning I succeeded to recover my account.
I checked my pages and I noticed that the page im talking about was unpublished.
I think its a case of Proxy change, do u regularly login from the same system, if yes, then might be u are being hacked or fb has recorded some suspicious activity which might be because
i. you are posting a already banned URL or repeated Post with Same URL or posting Nudity(Check the terms and conditions are, and what they refer to as nudity) Videos
ii. Might be someone else tried to login to your account and ended up blocking the profile, when a profile is deactivated all the pages get unpublished but you might go to All Pages>and check if your page is still there or not, if yes just go to the page and Publish it
iii. Facebook might have recorded unusual activity that can be explained only by facebook. so go ahead and appeal. Also check the new term & condition.
iv. Do you use software to directly post on facebook, Software might get tricky if u don't keep them updated
Why do i think you theory of removing admin is wrong
Removing admin is one of the features provided by Fb itself, so even fb cant unpublish u.
As fb mentioned your recent activity are not as per FB Pages terms & condition. There is something else might be doing that caught the eye. Go ahead and appeal if you can prove that the activity were not done by you. This might also let you know what you shouldn't have done, and dont forget to post here