It's been said before that the servers are kind of at capacity now and they can't add any more larger locations until SSOCS is completed. We currently see microTech scheduled for 3.8 but not SSOCS. Why is that?

They don't want to commit to release dates quite yet for SSOCS because things are still in flux. They can consider content swaps if they wanted to add in a new area and take something out to account for it. That said, no decisions have been made on that. Even if they released SSOCS earlier than they anticipated, they wouldn't know what the result would be because they'd have to measure. That is to say, any time an optimisation is implemented, they don't know if the job is done until they've taken a measurement to be able to conclude that it's working. So even after they've got SSOCS done, it's not a guarantee that they can keep increasing the content, and they may find that the gains aren't as much as they'd like, which would require them seeking other solutions. So these details will become more clear as the plan for SSOCS gets filled out and as they do more testing and can actually say with more confidence what the performance behaviour is.
Todd adds that microTech and New Babbage are still being built, so no matter what the Content Team will still be working on those locations. He continues to say that when they get the LODs, the AI, and all the other downstream dependencies in there, then that will give them an accurate profile for them to know whether the server will be able to handle it and if it can't, then they evaluate and consider taking something out, or the server can handle it and everything's okay. Part of the benefit of SSOCS is that it allows them to stream out areas where no Players are, but there's an unknown about how much that impacts the universe, because if your most expensive assets and content areas are the popular Landing Zones, depending on Player habits and where they go, they might find that those areas are constantly streamed in and are effectively pinned to always be streamed in.
So whilst they do stream out most of the PU, it can end up not impacting their performance issues that much because most of their performance issues are at those large Landing Zones. What they're more confident that SSOCS will do is make it so that the universe can be more detailed, so they could add much more outposts or truck stops or whatever, because if the server is capped at 50 Players then it doesn't matter if there's 1000 outposts, because only 50 can get loaded in at any given time. Chad says it gives a kind of upward maximum on the maximum distribution of what can be loaded in (I think he just means it increases their maximum load limit). But really it comes down to what the reality is in terms of performance, which they'll have to measure, because if the reality is that the Landing Zones get streamed out half of the time, then that might be good enough.
Jared specifically responds to why SSOCS isn't on the Roadmap, saying that it's not a list of things that are in development, but a list of things that they think and feel confident that they'll deliver on time to be included in a particular patch - it doesn't always work out that way, but with something as big as SSOCS they want to make sure they're more confident about when they can deliver it before adding it to the Roadmap.