I used your link and it reverted back to the "up to 40K miles" offer.
Yes like I posted 2 sentences under the link right below it when I tried the link it did that for me too.
I confirmed by logging into both My United account and my girlfriends and both of our have the offer on the homepage with a caption in a box that says
"You're IN" followed by the 60k offer.
Why don't a few other people log into their United #'s and see if they see the offer too.