I'm fine with having a separate set of Onslaught playlists, but those playlists should include ALL the maps, not just the four new ones.
It's gotten to the point that I rarely even go into the Onslaught playlists because I don't want to just play on 4 maps.
I think the best solution would be to alternate each lobby between new and old maps. That way you'll still be playing the new maps much more often, but not to the exclusion of the old maps.
Hey Apex Cheetah,
Previous COD games have had a pattern of offering a specific playlist option for a map pack right after it releases, and removing the previous map pack playlist, so it is likely this game will follow the same pattern. However, we cannot claim with any certainty what playlists will be in the future, since they are subject to change at any time.