Nobody can know anything right now: all our development tools are down.
Normally, editors might have some access to other editors' notes, which might give some information. But we don't discuss those publicly.
If I were to answer such a question, it would have to come down to either (1) the removal was justified by ODP guidelines, in my judgment or (2) the removal wasn't justified.
In case (2) there's no point, no possible gain to the directory, in discussing it with YOU--I could just fix it (discussing with other editors if I thought discussion was necessary.)
And in case (1) there's extremely good reason not to discuss it with you.
So, what do you do?
You can re-suggest the site, and an editor will re-review it (at that point determining whether it's a case 1 or case 2 situation, and determining which set of reasons for not discussing it with you are applicable--but in either case doing what the directory needs.)
There is a possible case 3 that you might be able to detect: if there were a mass removal of sites, and you looked at other removed sites and found that they were listable by ODP guidelines -- and you checked to make sure it wasn't just a matter of moving them to another category -- then it might be a pattern of abuse, and it might not be unreasonable to file an abuse report. (There are multiple possibilities other than abuse even in this case, so I emphasize that it "MAY OR MAY NOT" be abuse.)
And, right now, there's a possible case 4: crash-related problems. In that case, resuggest the site and try to avoid bugging the editors with questions without relevant practical consequence. (A "relevant practical consequence" is a case where you would need to do something different to help the editors build the directory, based on what answer you got for that question.)