Russia walked this backed:
https://www.reuters.com/business/energy/russia-will-not-demand-immediate-switch-gas-payments-roubles-kremlin-2022-03-30/Their messaging is confusing and their economy is too fragile to further restrict themselves from global commerce, so you can expect something like this to not go through. It sounded like an empty threat from the start and a mere desperate attempt to avoid sanctions. Appears Russia still has India and China open to them for unrestricted trading, but they cannot reasonable expect to cut off trading from the rest of Europe and keep their economy afloat.
I think for the time being they might have stayed away from this decision but eventually as their global commerce becomes normal I think you can expect they will easily implement this rule of paying only in rubles, one reason for that is also because they want to strengthen their currency's value as well which has actually taken a great toll after the recent war scenario, but for now they want to trade despite sanctions so atleast inflow of money isn't stopped altogether.
That's most likely going to happen in the future if inflow of cash is limited due to their conflicts but I'm also thinking that they want people to think that they aren't that desperate or as bad as people think but what happens happened already.