Don't quote me on this but I don't know if Europe alone will get a full pack--rather, we could get a Eurasian pack which gives us fallow deer but also animals like the Przewalski's horse and Amur leopard.As far as what i know North America pack is probably going to be last old type dlc ending 1st phase of frontier's roadmap (packs based on new mechanics are ment for december anyway). From next year we will see new way how frontier select animals for their packs. They can still make last regional pack Europe in spring, which would end FY22 for them. This sounds more logical to finish entire globe and then step FY23 with new format.
For me: NA (september) > birds (december) > Europe(spring) > new dlc type(summer)
(And I'd personally prefer a Pallas' cat to a lynx, but I might be in the minority there)