Yes, I think this is a meta tag based on the criteria of Jeff Atwood and his blog post:
- 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].
- 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.