It doesn’t help Ukraine? Of course it does. If it pulls Russian resources away from Ukraine to deal with a new terrorist threat, starts another Caucasus war, etc. The cover story tries to cast Putin in a poor light by saying that he had warnings and ignored them.
It didn’t help the Ukrainian cause to murder Dvogyns daughter with a car bomb either, but they did it.
With the size of Russia, and the number of people in it, I'm sure Russia doesn't need to pull any resources away from the Ukraine area. Hitler found that out the hard way.