It could be. It certainly tracks with the separatists’ move into guerilla tactics later in the second Chechen war.
Out of any time for them to start striking again, this would be it. Russia is stretched thin in manpower and supplies, and their attention is very focused on Ukraine and the West. Their ability to dump resources into the southern Caucus to tamp down a potential Chechen War #3 is definitely going to be limited. And coupled with the completion of Putin’s sham election, it sends a very strong message against Russia’s outward facade of “unity”.