As a data point, I know multiple people who've stayed at GHK on others accounts without an issue.
Data point.
Not to scare everyone as I'm sure this account was the exception to the rule.
When I tried checking in they said that I can't check in without the AH and they will charge me rack rate. They said there's a note in the account to make sure he checks in. Otherwise the hotel won't get reimbursed from gold passport.
I begged/ negotiated to no avail. After an hr we made up that they will give me a reduced rack rate and if I have the points in MY account by the time I checked OUT then, they can use points, otherwise it'll be the rack rate.
After I checked in on those terms and the account holder called the hotel on my behalf they called me to say they will make a one time exception and honor this reservation.
Again I spoke to many people that didn't have this issue but YMMV.