I only have this problem sometimes when I start the YouTube app...It hangs on the Youtube logo...Then I need to go to home again & start the YT app again but when it opens, I never had any freezing issues...
You guys can try force-stopping & data clear (or cache clear if you don't want to login to the YT app again) of YT app...This works on almost all android devices like u guys know...
P.S. I just got one major update 2680 which took total almost 10 minutes in downloading, installing & in the first boot-up after the update installation...