If you're playing this game due to raiding ... well, what else can I say at this point, you're doing it so wrong it becomes mathematically ... ok, let's not go there.
If you survived the drought of EC for one year, you'll survive this. Now that the development is split into "ground" game and GSF, it's only expected to see less focus on NiM.
There was no drought. EC was released on 4/12/2012, basically 5 months after launch. TfB came 9/26/2012, less than 6 months later, and was followed by NiM EC in November. April 2013 brought RotHC and S&V, less than 7 months after TfB, and an upgraded TfB. Their nightmare modes followed in June and July of 2013. And we all remember, DF and DP were released in October, 6 months after RotHC and S&V.
So in most cases, the NiM of operations has been released within a few months of the SM/HM release, with the exception of EC which was 7 months later, but we had TfB in the interim. And a brand new operation has appeared every 6 to 8 months.
In the case of DF/DP, they are releasing NiM 6 and 8 months after the HM version, and giving us nothing in the interim. Looking at the roadmap, it certainly appears that GSF remains their focus, to the detriment of all other types of gameplay.