Of course, but with Nintendo calling the system a home "first and foremost", i don't think it was a huge priority. I'd be happy to be proved wrong by 5-6 hours battery life.
I searched a bit but the first result on google is an old gaf thread and its content was... yikes.
Anyway looking at Nintendo's first party output, we consistently see games with no AA/post AA but many light sources and advanced lighting in general at high frame rates, so i'd assume that must mean they used deferred rendering for their first party output (Nintendo Land, Mario Kart 8, 3D World, Zelda, etc... maybe Xenoblade is forward?), especially considering that on Wii U's limited hardware they had to make some compromises compared to games we see on more powerful consoles today. There's also an interesting Shin'en quote that points to this, they went with forward rendering for Nano Assault and then switched to deferred with the second iteration of their engine used for FNR. Here it is:
Games like Trine 2 also ran better on Wii U compared to similar hardware, the game was sub HD on PS360 and struggled to maintain 30fps, while on Wii U it was 720p locked 30fps.
Here's a Nvidia article about it.