Are you illiterate?
If Whitebeard can't use Haki, then how the fuck was he fighting the Admirals who were all Logias? We literally see him hurt Akainu on panel.
Besides, a single panel alone is enough to throw your entire argument in the garbage where it belongs.
Fodders won't be wondering whether Kuzan was dead or not, if Whitebeard wasn't using Haki genius.