The way I see it, third parties are on the sidelines waiting to see how long the hype is for the Switch. If the Switch sells or outsells the WiiU's 13m by this time next year I think by E3 2018 we will start seeing ports of more AAA games from third parties with some downgrades (1080p vs 720p, 30fps vs 60 fps, less shadowing and Anti-Aliasing, etc.). Due to an increased market size for the Switch to sell games on. The market size is still very small at the moment (giving less incentive to put in work in ports) for the Switch compared to even the WiiU and is imo the reason Ultra Sun and Moon isn't on the Switch (see Gamefreaks Black and White 2 explanation).
At least until a new generation Switch is released (maybe with a Tegra X2 if/when the X3 is released by Nvidia) ala the treatment all Nintendo portables get. That should be able to run games with less compromises in visuals.