With all the things going on in the middle-east, a mostly defeated IS finds the time to attack Russia and Iran? If IS is not a US-op there is at least enough ideological overlap to work together.
There have most likely always been connections there. But imo the incentives for how to use IS changed once it became clear Iran and Russia where the big winners in the war against ISIS.
Let me save you the disappointment: they’re not going to be coming up with any substantial plan for de-dollarization. Even if they did, it would take decades to negotiate the terms between their members.