There are (currently) 18 questions tagged
And 13 questions tagged
Am I right in believing that these tags are meta-tags and need to be wiped off ?
1) could you have a question with ONLY this tag
I don't think so, [missing-files] and [data-loss] are better than [missing], [data] and [loss].
2) does the tag commonly mean different things to different people
Yes, people are left to wonder what is missing.
As [disappeared] is just a synonym tag to [missing] it is also a meta tag.