They opened the Niconico channel last week and announced the entire YNN site closing down today. End of an era.
The YNN site used to be a streaming site for Yoshimoto comedy stuff. They just decided to add an NMB option to it and it became a hit. The realities of running a streaming service probably caught up to them (YNN is famous for crashing during big live stream events) so they just decided to move the comedy to Osaka Channel and NMB too Niconico.
My experience with niconico is not too good either anyway everything remains the same (varieties and sections), the same stuff we had with ynn is now on niconico.
I really hate niconico because its a window to how bad Youtube could have been. Bad video quality and everything costs money.
You know, I always thought YNN is the actual edge NMB has in digital media platform. Extra content, job for member that otherwise may stuck in theater stage without light of exposure, extra content, etc. The loss of such channel set them back, two step at least. I'm not saying niconico is bad per se. It's free-2-watch with control mechanism to handle big stream(which favor P2W. Well, it's their money making way). Archive on the other hand..... As you said, end of an era. I'm half convinced that Naru show might have to be ended with the transfer of service. Maybe more than that.
It will depend how many paying customers follow them to niconico from YNN. How these subscription things work is they prey on laziness of the people who have subscribed to YNN maybe a long time ago and never bothered to cancel. If they force them all to cancel by closing YNN, these people might not come back anymore.