Thank you for pointing this out! I think checking the spec against those bug reports / user stories should be very helpful, in validating the spec. But please be aware, that the spec is not yet (fully) implemented in Ubuntu. Therefore, behavior on current real systems will be more as described in the “Status Quo” section than in the “definition of online” section.
Indeed, NetworkManager (i.e. nm-online -s) seems to be pretty lax with waiting for the online state (cf. nm-online(1)):
Wait for NetworkManager startup to complete, rather than waiting for network connectivity specifically. Startup is considered complete once NetworkManager has activated (or attempted to activate) every auto-activate connection which is available given the current network state.
So AFAIU, if you’re remote without wifi signal, NM will attempt to activate that connection profile, but fail and then mark “startup complete” and activate the network-online.target. According to the new “definition of online” this is NOT what we want. “network-online.target” should stay in a “pending” state, while booting of the multi-user.target or graphical.target should continue in parallel. (This has the potential to “block” the boot process if some services pull in the network-online.target , sort After=network-online.service and Before=multi-user.target at the same time, though. )