Indeed I am always disguested when someone says “send a mail”.
Maybe this is more common when English is not your native language; e.g. in Germany, "mail" is "Brief", and "email" is just "E-Mail" or more short "mail", because no one says "elektronischer Brief".
Interesting to see his take on “e-mail” vs “email”.
So that might just be the origin of this language butchering you observed; as "email" means something different in various languages, lots of people who don't speak English as their first language might have chosen to use "mail" for electronic mail. That is just speculation of course.
The question is though why pacman does not display these news during the update. Gentoo has been doing this for decades.