It's not in the status
matrix of benefits.
It's something hotels will usually offer to
all guests, regardless of status (which probably explains its absence from the matrix) - however the likelihood / duration will be influenced by status (unofficially of course, as none of this is written). The app blurb you posted above appears to all levels, including the no-status base level.
It's really up to individual hotels - I would say standard 1 hour late check out is almost a given (at any hotel, including non-Hiltons).
Even as a Diamond, most of the late check outs I've had are still at that one hour mark, sometimes I'll get 2-3 hours, occasionally I'll get as late as the check in time (3/4pm).
I've had a few hotels tell me they won't do late check outs as they prioritise early check ins - which I must say I get far more often, so I'm fine with that.