Hey FHMax3,
add Battle of Lenino to the list since it was mentioned quite a few times in changelog also there are textures for PzKpfw IV and FW 190 with Lenino suffix.
With this map a new faction would appear which is Polish People's Army or LWP (Ludowe Wojsko Polskie).
Sources (Why not let's be proffesional here
): changelog - "* Add Polish voices to beta (ts4ever)" or "* Remove crown from Polish Eagle in order to destroy the symbol of monarchist anti-revolutionaries (ts4ever)"
There is also a texture of T-34 with LWP's "Piast eagle" which is early polish white eagle whithout a crown.
Also T-50 and T-26 light tanks showed up on screenshots few years ago, they are also mentioned in changelog. Source: "* T50 update colmesh (kev4000)", "* Apcr ammo for t26 and bt7 (kev4000)".
Well these are some things I remeber, I was digging through changelog and files after last update so there might be more things that I don't remember, so check it if you want. Changelog is located in the FH2 main folder.
Oh and there was once a low res screenshot in this very thread on which people recognized a proper Fallschirmjager models. You could've spot this signature FJ baggy pants.
Well that's all sorry for any mistakes.
Cheers