Can you actually trade ruble? For some reason, for example, Sep-2022 futures chart for ruble has a gap between Jun 15 and today. And forex.com claims USD/RUB and EUR/RUB are unavailable for trading.
Yes, you can still trade it. Foreign currency exchange is decentralized. Us and EU exchanges have stopped trading and ruble, but you better believe in the n in Chinese exchanges still trade it
I think you are theorising too much based on a bit of Russian propaganda. I looked at a few exchanges and the spread on rubble is so high you could not buy more than a few dollars at the rated prices.