Lonewolf,
This isn't new - the RFAF have been doing this sort of routing over Iran/Iraq for months now. I can only assume that the Government of Iraq is content or it wouldn't happen. There's no need to overfly Turkey; fly from whichever home base down to Mozdok, stage there, route over the Caspian and hang a right over Tehran and keep going til you hit Raqqa, Dayr as Zawr or Aleppo. All this does is put the BACKFIRES a little bit closer to action and enables a more timely response.
But when you consider the range and payload of a BACKFIRE and the watch the video on RT of them dropping a dozen or so probable general purpose bombs, such a limited payload given the total capacity, and when set against the firepower they already have in Syria - FROGFOOT, FENCER, FULLBACK, not to mention HIND, HAVOCK and HOKUM attack aviation along with the odd TOS-1 thermobaric systems, dropping a few GP dumb bombs means very little. If I were a betting man, I'd say it was either a forward deployment tied in with the Kavkaz 16 exercise programme or an Info Ops / diplomatic move. Capability wise it adds very little. If it's not a demonstration or messaging piece, then the question to ask is just what exactly is wrong with all the fast air and attack aviation already in country? Where is the deficiency that they can't get the job done?