The new process might be quicker overall in general, world surface mapping not withstanding (which is a new feature anyway), but it doesn't seem to lend itself very well to knowing more upfront if a system might be one we want to explore in more detail, and for worlds and stars we can already visually see when entering a system, using the ADS map to find their basic information (like their relative locations), or potentially even being right near worlds or landing on them without "discovering" them, seems needlessly obstructive or redundant to me.
Ideally, I would prefer that the new mechanics provide additional information beyond the honk, but that the honk would still provide some basic information such as the system body count notification that we currently have, and bodies being target-able as hollow or monochrome bodies on the system map until "discovered" and manually target-able in supercruise like they currently are in the game. This could potentially be limited to moons, planets, and stars within line-of-sight, above a certain mass, and/or within a certain range. It might also create the opportunity to use the new mechanics selectively to find additional smaller body types or other phenomena that aren't yet implemented and might otherwise clutter up the current system map.
I think this also makes more sense for things like expeditions where we as players (and Commanders within the game) would already know that we want to rendezvous at a certain moon orbiting a certain world orbiting a certain star within a certain system even though we might not have been there ourselves yet. Of course being able to bookmark world surface locations and share bookmarks (dynamic system coordinate data, but not necessarily specific body data) would go a long way as a QoL improvement as well.
Regarding your specific suggestion, I like the idea, but I'm not sure how viable it would be to maintain these sort of data sets for each Commander individually or sort and distribute that information to them accordingly when going to a new (to them) system. I might be overlooking a simpler workaround though.
Edit: I suppose it might be doable with a time stamp check when entering a system, system discovery data sold time to last cartographic update time – you wouldn't actually be updating nor storing a personalized catalog of stellar system data when you update your cartographic catalogs, just updating a time stamp to be referenced on a case by case basis as needed. This of course assumes that the time the data was sold to Universal Cartographics is already stored as part of the metadata for individual body or system entries.