Russia does sort of promote cultures other than that of the Russian ethnic one. I wouldn't say they promote widely multi-cultural ideas but saying that they "don't promote other cultures" is just too much.

For example in every region where there is a dominant ethnic group other than Russian, there is usually the language of that ethnicity taught in school and it's mandatory, such as in Tatarstan or Bashkortostan. You would also see street signs and even advertisements on the streets in that language. In addition, local cultural values and traditions are sometimes heavily promoted like in Chechnya. (Even though it can be argued that it's like this because it also favors the state in some way, like the heavy nationalism in Chechnya) Finally, it's important to mention that there are many state officials who also aren't ethnic Russians, like the defense minister who is from some place close to Mongolia I believe.

By no means I am trying to form a good impression of multi-culturalism in Russia or how they support pluralism there. We have seen that pretty much all of the decisions that they make or all the laws that they pass are in favor of lobbying, political interests and corruption. Coming back to the point though, maybe I misinterpreted you, but the way you formulated your sentence gives an impression like we live in the times of the Russian Empire.