High latitude is no problem for polar orbits.
It's not, but it means your next generation rocket can launch commercial payloads to polar orbits and only polar orbits. Plesetsk is 62oN for heaven's sake. Fine as a secondary site, but you need somewhere further south as well.
That is not the way to build a meaningful revenue stream - there's a reason they don't launch all their Soyuz rockets from Plesetsk - because there's a military, government and commercial requirement to reach flatter orbits!
Angara as a commercial proposition is dead without a lower-latitude launch site. In principle, that shouldn't be too hard to arrange. But Vostochny has been beset by delays and setbacks, mostly thanks to inept management and Rogozin firing half the senior engineers at Roscosmos whilst buying himself a very nice dacha. They're not going to get a southern Angara complex up and running any time soon.
This station is one of the few things they could do from Plesetsk, if they launch to Molniya orbits, which may be the intent for this "lab", if it's supposed to have a long dwell time over the arctic.
The lab is intended to get a good view of potential Arctic shipping routes for the Kremlin.
It remains to be seen whether they can afford to actually design and build the thing though.
It does very much point to Roscosmos being increasingly able to serve only Russia's own private projects, being either too expensive or not having the capability to serve other launch profiles - a lot like Atlas/Delta. Everyone launched commercial payloads on Ariane, Proton or Soyuz until SpaceX came along. The US had priced themselves out of the commercial sector.