If there is money to be made on Nintendo's hardware, EA and Ubi will come.  

It's as simple as that. Don't overthink these things.

Ubisoft and EA haven't properly supported Nintendo in more than a decade.

The only reason they did stuff on Wii U was because they could get away with cheap cash-ins. It's what they do.

They've supported Nintendo consoles more in the last 10 years than the following companies:

Square-Enix

Capcom (yes, calling them out)

Konami

Rockstar/Take 2

Bandai-Namco

What games of EA would they put on the 3DS? They don`t really even put their games on the Vita, aside from sports games.

i don't think EA wanted to support handheld especially during the DS/PSP era due to piracy. EA really concentrate more on home consoles and PC as their main targeted owners.

Ubisoft supported Nintendo on certain IPs, not sure if it started only on AC V: Unity or even Rogue on why they didn't want Wii U to have any of those titles. Agree above on Square Enix, Konami, Take 2 that don't have games for the Wii U. Capcom has for the 3Ds SFIV 3D. maybe Tatsunoku v Capcom game for the Wii? so it is not 10 years back they didn't support Nintendo. They aren't just relative enough to push games.

But capcom should release a SF V to the Wii U i hope maybe after the PS exclusivity. Konami should try the PES on Wii U especially Japan gamers that bought the Wii U i assume would love football (soccer) and can have good sales. especially EA doesn't have their Fifa franchise on the Wii U besides the legacy edition of Fifa which we all know isn't great.

Ubisoft and EA go where the money is.
If Nintendo sells a lot of something then they will certainly be back.

It's not just about the number of games, it's about the quality of them. EA did quite a few games on Wii but almost all of them were complete junk.

Ubisoft probably will, not sure about EA though

The fact that the Wii U sells at a profit, the 3DS sells at a profit, Amiibos sell like crazy, the company overall is in the black and the only company that will have a net-profit at the end of generation is Nintendo because of the afformentioned circumstances, I predict that very few people will give a rat's ass if we ever see an Ubisoft or EA game on a Nintendo platform again.  I know I won't, investors won't, and neither will management.

I think its more Ubisoft and EA dont really see the value in handheld market anymore. They havnt realesed many games on the 3DS lately but they have released even less on the Vita.

Ubisoft even ported a Vita only Assasins Creed game to home consoles, due to the obviously larger install base but could also signify them leaving the handheld market to focus on home consoles.