gonna make it simple and give a myriad of reasons why it doesn't really matter much

1. NGS releases -> 99.99% of the player base is playing NGS
2. 00.01% of the player base is still playing PSO2 (this is you)
3. PSO2 is now a nostalgia trip for those who have been playing since release (returning players etc various other reasons)
4. Campaigns for people to go to PSO2 and do something there then go back to playing NGS
5. The class balancing for PSO2 likely won't even matter anymore if they completely stop updating it (which they will because the focus is on NGS) so while ya you can do your thing and break down more class numbers (which again, has been done by other people), its not very likely you're going to discover something nobody else know

you're thinking of PSO2 too highly to think that suddenly people a majority of people would flock back to PSO2 under your presumptions, NGS will be the complete focus for everyone and you already know they're not killing off PSO2, theyre just to keep doing the absolute minimal like they're doing now which could be anywhere from more random interval scratches cycling, rotating seasonals, obvious random EQs mayve every other hour or hourly. Don't know what theyre going to do exactly but it'll be for sure very low effort