Quote: "But apple are good at making things tricky for small devs."
Well, it doesn't seems to be that horrible to me if you are targeting Apple hardware. They provide all the tools and frameworks optimised for their own hardware and software, even a game framework and rendering engine for Metal. The Swift programming language also not that bad, looks similar to C# and Java. I can't really blame them for focusing on their own hardware and software only. if you are using some sort of cross-platform "one size fit all" solution like AppGameKit, there could be problems for sure but it is also true for other platforms like HTML5 and Android, these can be also a moving target even if you are using native JS and Java/Kotlin frameworks and languages because of the many different hardware and software combinations.
Anyhow to answer my own question, it seems it is going to be possible to build a Universal binary that is going to run on both Intel and ARM chips and Apple do work with many software companies to make the transition as simple as possible and even contribute to open-source projects like Blender. So TGC might be able to take advantage of this Universal binary Apple is working on to help with the transition.