Sadly, that’s false.
ACHTUNG! YAPPING!
To prove that, tell me how many Ukrainian (post-soviet) ground vehicles do you see there? How many Ukrainian planes do you see there? How many Ukainian ships do you see there? None.
If it was indeeed Soviet TT, we would’ve seen much more unique/modified designs in the tech-tree. For example, are Belorussian tanks/planes out there, in TT? Kazhakh? Azerbaijani? Armenian? And the rest? If we are so deadass, where are Estonia, Latvia, Lithuania? These are all ex-Soviet states, but where are these vehicles? In other TTs (Lithuanian Vilkas), or locked behind limited-time events (Belorussian-modernized Kazakh Su-25BM, in fact the only representative of ex-Soviet republic in whole Soviet TT, unless there is one or two I really missed).
What about ukrainian equipment? Where is it? It is in Chinese TT (ex-Ukrainian T-80UD and Chinese/Pakistani tanks powered by ukrainian-produced 6TD-1/2 engines), in Swedish TT (Finnish CT-CV 105HP and Swedish CV90105 using Ukrainian-developed and produced Falarick 105 ATGMs). They are not there, in Soviet TT, they are anywhere but there.
How long top tier exists? Or, rather, Ranks 6-7? More than 5 years? Wasn’t there a single Ukraianian developed and produced vehicle to include? Wasn’t there a single Ukrainian modified aircraft to include? There were, there are, there will be. But where are they?
Devs specifically keep Ukrainian modern equipment away from Soviet TT so you wouldn’t really know Ukraine is part of Soviet TT. To do that, you would need to google who made T-80UDs, T-64s, T-54 and so on. But there is no clear evidence of Ukrainian vehicles in Soviet TT, not even Ukrainian SSR if we are that deep into it. Is it fair? Absolutely not, as Ukraine, regardless of the year of 21st century, will, sadly, remain ex-Soviet state in history.
I can guarantee that Ukrainian vehicles are kept away from Soviet (or rather Russian at this point) TT intentionally. Is it because the game was “born” in Russia? Is it because devs don’t want to enrage their Russian playerbase? Is it because Western and CIS players, including Ukrainians, don’t want Ukraine to stay by the side of Russia (even if it is video game)? All these assumptions may have a place, but I did not hear a single justification on the topic of Ukrainian vehicles/equipment in Soviet TT from Gaijin officials.
I will repeat: I am not against Ukrainian vehicles/equipment to be in Soviet TT (it is not called Russian for now for a reason), but only if:
a) not the same type of nation representation as Canada/Australia. It is just horrible, a lot of people would agree with me.
b) rework/remaster/update of the UI for large nations. Ukraine can easilly benefit from at least 3 lines, but squeezing it into existing ones will bloat an already large TT. I like @MAUSWAFFE’s suggestion of nation folders.
c) no captured modern equipment. I am against T-90M with American flag on it in the US TT and so against CV9040/M1A1/Leo 2A4 with Russian flag and "Z"s across the entire vehicles. If we want Leo for Soviets, just add Leopard 2A4V with Ukrainian flag on it, as a part of sub-TT, like @Yontzee has already suggested.
I hope that kind of explains some things, at least from my POV. Also, mods, if I somehow touch them politics too much in this post, tell me where shall I edit stuff or remove it.