I believe what was stated by Mr. Lind shortly after the announcement of this DLC is that, there will be no more BIG DLC's like MTG or NSB but instead small to medium size DLC's to focus on areas that have not been touched such as Middle East, Scandinavia , South America etc. that have no dedicated focus trees.
While I agree Finland needs attention, I think them including it in a Scandinavian DLC is much more logical, even though there was a short war between SOV and FIN, with the direction Gold Studio is going with HOI now, ahistorical seems to be dominating rather than a railroaded WWII sim and a focus tree for FIN relating to other Scandinavian countries makes more sense.
We needed a SOV focus tree sooner than FIN and they can't do everything at once. But we also need an Italy focus tree as well...