Are you suggesting that non-standard shaping of screens is a good thing or a bad thing?

I personally think it's a bad thing, unless you have a specific use case in mind. For 99.99% of use cases, rectangular screens are a pretty good choice.

I don't think GP is suggesting either, rather that non-rectangular screens are _a thing that happens_ and many are not prepared to deal with it because they didn't think of it. In the same vein of the "Falsehood programmers believe about x" articles.

But at the same time, just about every software engineering decision has a long tail of oddball edge cases. You could use any of these to justify a new "Falsehoods Programmers Believe About X" principle, but for many of them it's (in my opinion) vacuous to bother because it's either unnecessary to deal with it or it's legitimately strange and exceptionally suboptimal for the client to be designed that way.

For example, I don't really have a problem with the way Youtube presents itself on the iPhone X screen in landscape mode. It's not perfect, but nothing is actually breaking. There is some unused screen real estate. There isn't so much a falsehood here as an aversion to a more sophisticated screen filling methodology. If someone were to view YouTube in a screen shaped like a circle, the YouTube developers would have a strong argument that's not a fact of life but an oddball thing to do, and consequently not support it.

Conversely there are legitimate consequences if you make false assumptions about e.g. foreign language encodings, email validation, characters present in human names, etc. These are domains with edge cases that have a huge number of unknown unknowns due to very culturally significant and non-dismissable reasons. You also can't really skimp out on designing for them because doing so could completely break functionality or introduce security vulnerabilities.

It'll be interesting to see if Apple ever make a circular Apple Watch. I can see a scenario where the strap even incorporates some flexible screen which would be utilised for additional status and content.

Instead of cartesian coordinates, you could just program it using polar coordinates. And ring buffers.

There are already plenty of circular Android Wear, so it's far from impossible.

Or, don't design around gimmicks and fads. The "falseholds programmers belive" are overblown, usually non-issues, and frankly probably aren't worth the development time to support.