Although this was 1-2 years ago:
A VEX Speaker emits, yet does not sense, but it is still considered a custom sensor by the GDC’s standards if they receive a command within robot’s program. LED strips emit, and they don’t sense, so we can likely use the VEX 3rd party speaker rule as a projection of what is to be expected if it were ruled this year.
So when I was meaning “by definition,” I was meaning the definitions that the GDC placed on specific items within the past. These can be re-clarified, of course, but unless they are re-clarified my common sense would result to previous rulings within previous years.