That's a good read and I especially like the attention you gave to how things were in the 80's and 90's and how the artwork was perceived back then.
Just a small correction: under the heading "2.) The way sprites are rotated:" , you say "This usually requires us to draw multiple rotated images and clean them up by hand, which also results in more work." hmm... if anyone is actually doing this, it's a phenomenal waste of time, I've never actually heard of doing it that way! The issue is easily solved by the "Low resolution setup" you described in your heading "A “Pixel-perfect” setup:" If the game's output is rendered to a low resolution pixel buffer (eg. 480x270) and then scaled up with no filtering to 1920x1080, you will get a "pixel perfect" result, meaning all sprites will stay on the pixel grid and all rotations will look "twinkly" just like they did on the SNES, as in the 2rd cup image, rather than seeing individual rotated pixels as in the 3rd cup image. Effectively, the game is emulating old hardware by first rendering the game to a virtual "low resolution screen" before scaling the whole thing up to fill the hardware display in real life.
Also I'm curious what you mean by "There is however no agreement if the user then stretches the view." Do you mean running in "windowed mode" perhaps? As the developer, you have complete control over how the game behaves at different screen sizes and the user need not "destroy" the aesthetic by "stretching the view". If the goal is to maintain sharp pixels at different display sizes, you can do this, and there are several options available to you. It's the same scenario as in the beginning of your article - you need to know what hardware displays you're targeting and design the game to look good on those displays. In modern times, we can afford the game to be "responsive" and adjust itself to look good on a variety of screen ratios and resolutions. Usually by cropping and adjusting the GUI to align with the edges properly. Of course you can just scale and apply filtering and have slightly fuzzy pixels but not have to do any tweaking for different display sizes.
I like your notion of being "consistent", that's the key in any good artwork and the one thing that matters above all else.
As for myself, I used to prefer all pixel art games to render to the low resolution pixel buffer first as above, but after seeing all the amazing pixel art games that play with the limitations, I've come to a similar 2 options you have I think, I just like to define them a little further:
1. For a nostalgic option, I like the idea of "faithfully retro" games that only render to the low resolution pixel buffer, and never use any transparencies or any gradient effects, only using GPU shaders to emulate old hardware effects like scanline effects and palette swapping effects. And then on top of that, sticking to the colour and sprite size limitations of the hardware you're pretending to be. This is only necessary when you want to hit a target audience that wants to see your game and feel like they would have seen this kind of game growing up in the 80's or 90's.
2. For a modern pixel art aesthetic, It's enough that the pixels are all of a consistent size, but it's rendered to the high resolution display with the individual elements scaled up by the same amount, meaning they move in "less than 1 pixel increments" for smoother movement, and rotations show the actual rotated pixels, and they are free to add lighting effects and gradient colours, transparency, glowing effects, particles etc. as they see fit to fit their artistic vision. It's great that the pixel art aesthetic is hanging around through this approach and being appreciated by a new, younger audience.