@Thirstday It's worth noting that the "Items Obtained in PSO2 That Cannot Be Used in PSO2: NGS" section does not mention anything about cosmetics, and that this is said as well:
The information provided on this page is for a game still under development. The content and specifications may change at any time without notification.
Along with this:
For weapons pertaining to classes that have not yet been added to PSO2: NGS, they will be unusable until the relevant class has been released.
They said that for weapons but not for cosmetics. If not all cosmetics would be available on release, they would mention that in the same way that they've done here unless they are intentionally hiding that, or it was an oversight.
Like you say, we're not SEGA. However with the information given by them and the vagueness surrounding cosmetics, I'm not surprised that people are assuming all cosmetics from PSO2 will be available from the get-go. They wouldn't be saying "all character creation info" if that wasn't the case.