With PS5 and Xbox Series X coming out at the end of the year, do you think Switch will get ports in 2020 and beyond? I don't think so. Here's why: With the launch of new consoles, developers will be porting games in a short time frame. This means less engineering bandwidth available for Switch.
Second, with next gen consoles having 30x the GPU capability (Switch handheld - handheld is the limiting factor), less focus will be given to scaling down, and more focus given to scaling up. Some games like Cyberpunk 2077 have reportedly had issues with the base Xbox One. This rules out a Switch port IMO. Unless it's farmed out to a porting house, and the game's content and engine allow it, it's probably not going to happen.
Third is new engines. Related to point 2, but worth expanding on, developers will be working with new engines because of the console launches. Probably not until 2021 or 2022, but it's going to happen. Better lighting and shading techniques comes from the research community. As an example, deferred shading was first written about in 1988. There's a surplus of good research that's already been done, but not implementable efficiently, mostly because hardware hasn't quite caught up yet. My prediction is that developers will try to reduce bake times and improve quality by using techniques the Switch can't handle at target frame-rate. My prediction is that Switch gets left behind. I'd like to be wrong, but it's the conclusion I've come to by looking at the data available.
Currently (Re-)Playing: Starcraft 2: Legacy of the Void Multiplayer, The Legend of Zelda: A Link to the Past
Currently Watching: The Shield, Stein's;Gate, Narcos