'sensitive' designated revoker -- are the keyservers still aware?

[snowcrash+gnupg-users]

if i've added a designated revoker to a key, WITH the 'sensitive' flag.

am i correct that:

(1) the 'sensitive' flag prevents the *export* of the add'l/designated
revoker's key
(2) the keyservers still learn/know that there IS a designated
revoker, AND its KeyID/UID

?

thanks.