Speaking of Paralay's forum, seems like the overall current consensus is between this being related to PAK DA or Tu-22M modernization. Some questions have been raised regarding the four crew layout and how that may be fit into a flying wing design.
I personally think that a four crew layout isn't inherently off limits for a flying wing VLO bomber, the guys in the back would just be tucked away with very smol top facing windows I'd assume similar to the WSO on a MiG-31 or SR-71 where the back seat doesn't protude from the fuselage or gets an extension of a large glass canopy like on an F-15 or Su-30.
Could also be related to Tu-22 modernization, who knows. But I'm unsure how much Russia wants to invest into the aging Tu-22s which are burning through their flight hours and can't be replaced IIRC (I could be wrong here, anyone who knows better feel free to correct me). Unlike the Tu-160s where modernization makes sense and new units are actually produced nowadays.
If it is actually related to PAK DA it's certainly very neat. And I personally don't see much issue with retaining four people over reducing the crew to two. I can imagine this gives some opportunities with regards to managing information collected by other airborne or even ground based assets, drone control etc.