I also strongly doubt the Other European Airlines forum can be 'home' for Finnair, or any other Airline/FFP for that matter, at its present state. Whether this is more an issue of a need for a separate AY forum or better management of the OEA, I don't know, but at the moment OAE is not homey and cozy at all, and I would go to lenghts to say it prevents generation of good discussion and establishment of community.
You may note, for example, that at OEA forum, there are currently one thread related to Austrian Airlines and one on LOT, both of which should go under Miles&More forum, if I've understood currently. While this is quite frequent misoposting, these two threads are actually moved there by moderators from other fora. So, if even mods don't know which airline belongs where, how would a sporadic visitor know?
Recently somebody was adviced to ask at other european airlines forum instead (I don't remeber where, I think it was AA forum), and the OP replied something along the lines 'Which other European airline forum should I ask?'
Whilst I understand the need to have a critical mass of interest to create a functional forum, I don't think these geographically divided 'other fora' make the trick. The case might be different if the OEA forum had dedicated moderators, who would organise master threads on airlines/FFPs to be discussed there, and update the info regularly. However, I doubt this is a realistic scenario.
Therefore, I think Finnair, and any other airline that has a genuinely interested potential community, should at least be given a try with an own forum. Isn't it the whole idea of FlyerTalk to generate meaningful frequent flying related discussion?