This has implications if some packages were to ship Wants=network-online.target by default, which I believe is already the case. Such a package would never start its service on a laptop that is offline. This might break user expectations. Some users would expect a service to be available on localhost even on a laptop that is offline. For example, right now in Jammy, lighttpd, inspircd, openbsd-inetd, squid all declare this. I haven’t fully tested if this means that the service would be unavailable. dovecot does seem to be in this list but I noticed that it also declares a socket unit for example, so I’m not sure why dovecot is started by default at all. But it’s something to consider. lighttpd for example is perhaps the clearest in the above list in terms of services that users could reasonably expect to be available locally even when offline.
Maybe we will decide in Ubuntu that packaging that declares After/Wants=network-online.target is buggy in the general case. But then, if we decide that services should generally be available on localhost if that makes any sense at all, including on offline laptops, the problem will be maintaining that Ubuntu-specific delta against Debian packages that already do it, since we’d have made it an Ubuntu-specific problem.
I’m not trying to argue either way here. I have yet to form an opinion, and am just pointing out the implications of going in that direction.