Is it really this info ? If yes when we can travel from Russia to North Koreea via Usurjisk-Khasan ?
Well, in many cases it is not the best thing to trust the source from where you took this info or at least there is always a need to recheck it
In this very case it is wrong because:
1) Pyongyang carriages via China are still running and you can purchase tickets for those, they are still in timetable (till 10/12, last departure dare before timetable change) etc.
2) No info whatsoever about such thing in Russian speaking internet or RZD/MZA websites. RZD/MZA and Russian speaking forums would be exactly the place to search for such things, but your "source", as far as we know, doesn't even speak Russian to check it
3) Huge changes like this usually not happen in the middle of the season.
Another inaccuracy is that Khasan-Tumangan crossing is closed for foreigners. It is not true, we know at least couple cases of successful border crossing there by non Russian/Korean citizens, exactly Moscow- Pyongyang carriage was used.