No idea, neither my department or my right to comment on that. From a purely technical point of view, any jailbreaker will note that those apps are in the read only system partition though, so they don't take any space that you could actually use even if you did delete them.

You can always just move all their icons off to the last app page and forget about them, though. I disagree a bit with you about mail and maps, they work fine for me.

Yahoo isn't a built in app...