I don't know the specific answer for Finnair, but based on experiences with other airlines in the past (including AA), just because a carrier allows you to select several different vegetarian meals "on paper" doesn't mean that those meals are really different. They may create, for example, a vegan meal and offer it also as the lacto meal, since the lacto meal says it "may" (rather than "does") include dairy. For years (before they finally admitted that there was only one vegetarian meal), for example, AA would always give me (transfatty!) margarine instead of butter as part of my supposedly "lacto/ovo" meals, and I wouldn't get yogurt for breakfast (just fruit, fruit, and more fruit). Furthermore, I think the exact same meal was also offered as the "low salt" meal, the "low fat" meal, etc!

And the CSRs never knew this, because they only saw what was "on paper".

And websites which compiled info only from the official sources (not from actual travelers) never knew this either, again because they were using the listings only.