Fossapup is more recent than Bionic, but ageing. Apt/dpkg is a fine package management system, but been available since 2013 here via DebianDogs with similar features in terms of functionality, size, and flexibility to Pups whilst being very compatible with upstream Debian or Ubuntu, but that didn't prevent release of BionicPup nor Fossapup so no reason there couldn't be a JammyPup, for example, but I've only noticed a 32bit release in that direction, which would be for much smaller audience that still uses 32bit distros I suppose. Of the apt/dpkg capable new Pups, I prefer Vupup, though originally that was also because I didn't like Vdpup when it was first released (and haven't kept track of it since) - overall, I tend to prefer Ubuntu-based distros myself, when apt being used, but that's just a personal preference.
I like VoidPup because it remains a pup in the sense that it also intentionally handles dotpets via PPM (not that I like PPM, but Puppy has always prided itself in having PPM dotpet capability no matter whether you were using a Slacko, Debian, Ubuntu or whatever based Pup), though xbps is a big winner - reason I like that one is that upstream Void isn't itself such a huge distro so its packages seem to me to fit well with Puppy lesser-bloat-philosophy whereas apt/dpkg makes distros using that package manager just another 'Debian/Ubuntu' distro overall.
KLV-Airedale (also using Void's xbps) isn't a Pup at all, though the idea of a 'Kennel' release is a different concept anyway, since the idea allows for using component parts from any distro project featured on this forum - but it certainly isn't 'Puppy Linux'; as a separate distro it might benefit itself from being notified to Distrowatch since most of the Linux world probably doesn't know it exists.
Puppy Linux own identity has been stated as via woof-CE creation - I thought both Vupup and Vdpup were produced via official woof-CE, but reading above posts it seems the Vanilla Pups might be created from a dimkr fork of woof-CE with some parts not pushed back into woof-CE official? I don't know about VoidPups relation to official woof-CE either - maybe forks it and then adds extras externally? Is there any other Pup being considered as an official release - for example, is there a Jammy64 release being worked on somewhere(?). Puppylinux.com homesite doesn't indicate any new official releases that I've noticed so nothing seems to be designated 'official' at the moment, which makes the Distrowatch submission a bit tricky.
One type of distro I wouldn't put on Distrowatch are 'remasters' - these are just revamped versions of the originals. The originals are the main developments overall in the sense that they are constructed from a reproducable build system. Some remasters are excellent of course, so my comment is debatable.
Would seem to me that VoidPup, Vdpup, and Vupup are all recent and maintained Puppy releases. They are all somewhat different so seems to me they all need notified to Distrowatch if presence wanted there. EasyOS already there, as if FatDog I believe. KLV not. DebianDogs, never that I noticed.