I am rather curious as to the precise nature of any Russian action in Syria.
I certainly do not see a full blown all fronts Russian led offensive, but rather hark back to the notion of Putin being an intelligence man and a master at playing the smallest possible stroke to spike the guns of his opponents.
At the back of this, is the nagging suspicion that many of the recent moves by Western powers are primarily positioning to resume the regime change agenda and that is is this that has prompted Russia to up its activities.
I suspect that the Turkish border is the key here. The Western strip is safe Government territory, while the East is Kurdish or ISIS controlled. This had left the province of Idleb as an area open to Western friendly forces and from where a powerful ground force backed with air cover could attempt to overrun the key Government held areas.
I suspect therefore that Russian forces; including ground and Air Power will be used to retake Idlib to the Turkish border and close this gap for good. Putting Russian troops on the ground and I would suspect, taking control of the border section would ensure no counter strikes by Western forces should the Syrian Army attempt the recapture on its own.
The notion of then assisting with other pocket (cauldron) liquidation operations seem realistic as well.
The west has always seemed more interested in regime change than fighting ISIS.
Your theory would neatly explain why the Russians are making moves now - sending in a Typhoon SSBN seemed an odd choice against ISIS, but as a counter against further western misadvantures in Syria, it would actually make sense to choose that asset to deploy, rather than, say one of their SSGNs.
It also explains also why the fairly modest Russian deployments already on site (a hand full of tanks, some infantry and supporting air assets), which are totally understandable responses by the Russians given the security situation in the country, would stir up such anxiety and consternation in certain western capitals when, on the face of it, another powerful country getting more actively engaged in fighting ISIS should have been a most welcome development.
If this is true, the Great Game is still on, and the Russians are playing it well.