Video games establish and follow rules… that’s what makes it a game.
You’re right, they did make it clear. To quote the patch notes:
The goal was to make it so her ult couldn’t be farmed at insane speeds by tanks with large health pools. I can agree that, that needed to go. Giving her ultimate charge gain off of self-healing would still accomplish that goal. Sombra’s 200 hp would act as a “cap” to how much charge could be gained from a single pack – making it still charge EMP slower than it did before, while maintaining some benefit to picking it up.