It appears that Premiering doesn't cover only the a true new shows first episode? Because I see two episode (season 10 episodes 1 and 3 on CBS) of Roseanne.
These are also marked as New.
How about some more useful for Roku like filter by channel. Only 6 out of the 19 channels I receive are main Network channels(CBS,ABC,NBC, FOX, CW, and PBS). Many of the other sub-channels have shows from the 60's,70's, and 80's.
The Roku PrimeTime filter doesn't seem all that useful since it includes tons of these shows plus a raft of cooking shows.