From what I've been told, full support as it's becoming obsolete is mostly the point. Running Linux on a highly closed and manufacturer hostile system will never be a good experience. Anyone who wants a Linux machine will buy a frame.work, system76, Lenovo or Dell, etc, not an apple. The point of linux support here is to give the device a longer life once apple drops support. In other words, when the hardware is no longer a sufficient apple machine and is more of a toy, at least it will be possible to put something else on it.
You've been told wrong; our goal is absolutely to catch up to Apple's hardware cadence and make Linux on Apple Silicon something people want to run as an alternative to macOS, well within the platform's support lifetime.
I think it's entirely doable, especially with the interest the platform has. There will always be things macOS does better, but there are also things Linux will do better.
Personally, I'll consider the project at success if we can match or exceed the features and stability of an average x86 laptop running Linux, with the performance and power efficiency advantages that Apple Silicon brings, which I think is totally possible.
Apple doesn't throw away their SoC design and start from scratch. Future iterations will share much of the same code. For example, the interrupt controller and the UART hardware haven't really changed since the first iPhones.