One of the things I could point out is that we don't exactly know how Sega's resources are "limited" because for what I can see they seem to be on-track being consistent with how they have been over the years.
It definitely can be questioned and improved but Sega has always been dripping "content" in droplets and it isn't surprising when that content is already cleared within hours if it isn't time-gated. Their roadmap already shows their plans for what they want to do and I would imagine that most of that is already addressed or being worked on simultaneously alongside one another - but simply just not released or release-ready yet.
I feel to be fair and to be real about this, Sega is a Japanese company that in a lot of ways is still very much stuck in the past for better or worse. Phantasy Star Online 2 has adapted to the times (to varying degrees of success and dismay) but it didn't happen in the same speeds and the same paces you expect out of "modern" software development.
Along those same lines, I recall the director of New Genesis is currently the same director of Episode 5 (when the game took a direction to saying "Buster Quests-only" and dedicated all of its content to the Hero who at the time was the only class viable and capable of handling said content while gutting out every other form of "content" because all their eggs were in the basket for the Hero and Buster Quests).
In conclusion, I feel relatively confident that the content is coming - just simply not at any of the speeds you are expecting in relation to global and ultimately not until about a half-year from now at minimum. My guess for content is that you're likely wanting a full story - which likely won't be years from now even.
Edit: I know I mentioned this elsewhere, but you can imagine that it took Phantasy Star Onilne 2 "years" to find its current gameplay loop. I don't quite know if Sega's ideal of a gameplay loop is what you want (repeating the same current trending quests for loot) but the goalpost has always moved with each year - each newer one invalidating the previous.