I have an idea why Link's Awakening was remade.
Look at the upcoming Playstation 5 and Xbox Two consoles which will include ray tracing technology. AMD GPUs are going into that while the Switch has a Nvidia GPU inside (I know system on chip and it's called Tegra). Those new consoles are going to be pretty good and offer up to 120 frames per second which seems to be the norm on 4K TVs these days plus better lighting in games thanks to that ray tracing technology. Happens every generation and this will be a big jump in graphics overall not seen since maybe the PS1 to PS2 jump if not the PS2 to PS3 jump.
The original Link's Awakening was intended to be a port of A Link To The Past (for the SNES) for the original Gameboy and was used by the devs to test the capabilities of the Gameboy and ended up being its own Zelda entry which turned out to be very good. That was truly amazing work by Nintendo when you compare the original Gameboy to the SNES back then. Even LA for the Gameboy moved more smoothly than ALTTP despite using smaller frames and a smaller overall map while ALTTP had bigger frames and essentially two maps.
I know that the importance of graphics is overblown more often than not but Nintendo (like the rest of the public) already has a general idea of what the next generation games are going to look like (and some third party devs might have been sharing some details with the Big N...happens all the time in the industry) and needed a way to show potential Switch buyers that the Switch is capable of some real pretty graphics. Given that LA was also remade for the Gameboy Color and the map size of LA was pretty small, it made sense to have Nintendo use that game as a way to demonstrate the abilities of the Switch just like with the Gameboy and Gameboy Color. Nintendo isn't just merely courting future Switch owners but game devs as well so the Switch can have as long of a shelf life as possible before making way for a successor to the Switch. Given the history of LA, it also made sense to remake LA for the Switch. If that wasn't the case, LA for the Switch would have been performing at 60 fps just like A Link Across Worlds on the 3DS family of handheld systems. That explains why LA is draining the Switch's battery at least as fast as BoTW did. I'm hoping for a performance patch that would allow us to play at 60 fps even if it means lowering the graphical quality of the game...it's nice to have options.
As for Nvidia, it was an opportunity to show what their Tegra SoCs are capable of because AMD is putting Radeon GPUs into Samsung phones and tablets in the not too distant future. Nintendo & Nvidia had something to prove and this was the perfect way to do this.
As for the remake being necessary, it was great not having to constantly remap the buttons and also you need twice the secret seashells to get the L-2 sword compared to the Gameboy versions of LA. Also 32 heart pieces for the Switch compared to 12 for the Gameboy versions. Plus more Quality of Life improvements in the Switch version of LA. As for the Oracle games not being used for a remake, the Oracle games were developed for the Gameboy Color which was more powerful than even the original NES and maybe on par with the SNES so Capcom & Nintendo were able to make bigger frames compared to LA. The Oracle games would have not looked as good as LA did so that is why LA was chosen in this case.
As for Minish Cap, that game is probably coming to the Switch when GBA games are included with Nintendo Online subscriptions either in 2020 or 2021 given that there is to be four different systems (thanks to data mining) and we already have two of the four in the NES & SNES. Given that the Switch is a replacement for the Wii U, it appears that the Switch will have the same virtual console systems included the Switch Online plan as the Wii U and the Wii U had NES, SNES, N64, and GBA games in addition to DS games which isn't going to happen on the Switch at this point. I liked Minish Cap and wouldn't mind a remake but those GBA games might end up aging very well over time that a remake might not be as necessary until further down the road.