It’s both
I agree. It's both an ad and a useful signal of where the code came from or how it was created.
Just like the default iPhone email signature, it's an ad and a hint that the author was typing with their thumbs, so it's probably a brief auto-corrected message for that reason.
Which for my repositories means I want ~95% less of it in my commit history. I'm prepared to round up for simplicity. But to each their own.