Hm, so the leak was somehow vaild, they changed a little bit. Tundra still not that powerfull, but it is like coasttile a good option to limit your city growth. Cossacks are stronger in general and can move after attack from the start, but wasnt there a promotion for light cavalry which did the same?
So trade routes give always the bonus, better then that limitation. Good to couple with the trader union civic or what it was called which does the exact same.
And Holy Site special district, hm, so you should be quite save to get your religion and yeah, great person for an extra tile, it is somehow usefull regarding all those lets plays where money is somehow always a problem.
The strongest part of Russia obviously is the bigger space all new found cities get. Regarding all those lets plays the first settler wave for everyone is leading to a fight for the fresh water places on rivers/lakes/oasis. More tile grabbed will probably deny other's landgrabbing. But Im still somehow not that hyped about Russia ...
So Percia will come in the near future after the release ...