Quoting the political situation, they have removed installers from their webshop and will work on removing certain features from present versions 4.3 and higher. They did not explicitly say so, but I guess its about certain features and techncial and procedural details in at least some tanks being so realistic that it is no longer an option to publish them freely while Russia increasingly poses a threat in the real world.
I understand they want to be back, but the pause can be lasting several months, since it is about rebalancing the game version available to the wide public completely.
https://www.steelbeasts.com/topic/18090-esim-site-down/
One could be disappointed if one were a new customer interested to get embarked on SBP. On the other hand that they see the need to do what they just announced and explained is a compliment to the high amount of realism in their sim.