U sure about that?
EAD Group 1 released Mario Kart 8 in May 2014 and worked on DLC for about a year.
EAD Group 2 released Splatoon & Animal Crossing: Happy Home Designer in mid-2015.
EAD Group 4 released Super Mario Maker in September 2015, Pikmin 4 in development but without a specified platform.
EAD Tokyo released Super Mario 3D World in November 2013 followed by Captain Toad: Treasure Tracker in November 2014.
Retro Studios released Donkey Kong Country: Tropical Freeze in February 2014.
Hal Laboratories released Kirby: Triple Deluxe in January 2014 followed by Kirby: Rainbow Curse in February 2015.
Intelligent Systems released Fire Emblem: Fates in June 2015.
ND Cube released Mario Party 10 & Animal Crossing: Amiibo Festival in 2015.
Monolith Soft released Xenoblade Chronicles X in April 2015.
Do u think these teams that finished projects in 2014/2015 are working on new 3DS/Wii U projects or have moved on to NX?
Let's look at the Nintendo IP releasing this year, Mario & Luigi: Paper Jam (outsourced, 2015 localization), Fire Emblem: Fates (2015 localization), Twilight Princess HD (outsourced, HD port), Hyrule Warriors Legends (outsourced port), Pokken Tournament (outsourced, 2015 localization), Star Fox Zero (co-developed, delayed 2015 title), SMT x Fire Emblem (outsourced, 2015 localization), Metroid Prime: Federation Force (outsourced), Legend of Zelda U (delayed 2015 title).
With the exception of EAD Group 5 co-developing Star Fox & EAD Group 3 working on Legend of Zelda (could be cross-gen) there are no known internal studios or subsidiaries working on 3DS or Wii U titles. Nintendo is most likely working full force on NX titles.
EAD Group 1: Sure, but they are usually responsible some of the bigger games, and if they're working on a launch title i'd imagine it'd be fairly big, so i doubt it would only have a 1-1.5 year dev cycle.
EAD Group 2: Pretty much EAD Group 1.
EAD Group 4: As i said, Pikmin 4 may possibly be an NX title, but it can very much be a Wii U title as well.
EAD Tokyo: Perhaps, but depends on when they have been given a dev kit, if they've been given one at all.
Retro: Their last game released early 2014, about 2.5 years before when people think the NX will release. I doubt they were given dev kits back then, so they must be working on something else.
HAL: They could release a game for 2016, in the caliber of Rainbow Curse.
Intelligent: I imagine they've just finished the translation not too long ago, and even if they outsourced that to another developer, still not enough time.
ND Cube: They could pump a game in-time for late 2016.
Monolith: They tend to have gaping development times, so they're not really a good source for when the NX is releasing :P
For your question: "Do u think these teams that finished projects in 2014/2015 are working on new 3DS/Wii U projects or have moved on to NX?" Sure they can be working on 3DS/Wii U titles, you're just simply riding on the assumption that the NX is releasing in 2016. For all we could know, we could just get a speckle of details this year on the NX and it could release in a few years.
As I said, we won't know anything until we get details, so we should just wait. But as for what the studios are up to, you're pretty much right in saying a lot of them are working on unannounced games, which could of course be NX titles.
EAD Group 1: but you have to take into consideration that Mario Kart games NEVER Launch with the console, and, since they need a 3 year development for a MK game they could release it by the end of the 1st year of NX/during the 2nd year .
EAD Group 2: both Splatoon and AC:Amiibo festival didn't need many developers and development for both (counting a few months after release for the additional weapons in Splatoon + additional bug fixes) ended probably in July/August 2015 leaving pleanty of timeto make other games/working on the new console interface;
EAD Group 4: Again, team that is confirmed to be split due to Pikmin+SMM, I think the development of the latter might be one of those who took the lesser ammount of developers in Nintendo's recent history, Pikmin HAS TO BE an NX title, if it is a Wii U title it'd be in Nintendo's interest to keep it a secret so that they can surprise us at E3, instead Miyamoto threw it out there as if it was nothing;
EAD Tokyo: since Captain Toad used the same engine as SM3DW it's likely too that most devs started working on the next Mario game right back in 2013...
Retro: There's something called moving projects to other platform, it's what happened with Star Fox Zero that was originally a tech demo for the Wii, also I wouldn't be so shure about the dev kits assignements inside Nintendo...
HAL: Imho they have had somethinkg big under the curtains since they've been releasing simil-minigames lately
Intelligent: Translations are made b other companies, development ended in March 2015 or a few months after that considering DLC, still they might be able to publish something by the end of 2016/early 2017
ND Cube: as you said, they could release something by the end of the year EASILY
Monolith: Their development cycle doesn't count since they release games after 4/5 years :v