Regardless of any other fact (or logical conclusion from analysing a fact, such as reading roadmap state), this right here, means that SQ42 is very close to completion.
No sane CEO would move his family and drastically change his entire personal life (and lifestyle) for a long period of time, while a product is still being made (as opposed to near completion).
Not to mention he's leaving his headquarters (LA studios) behind... this is not like moving the company from one place to another. So yeah, SQ42 might be closer than we think.
I'd dare say even, that the game might be long before their 10 year anniversary... but for marketing and sentiment sake, that may very well be their release date... and what a surprise it would be... Announcing SQ42 at citcon 2022!!!
As for the rest, it's not that I don't disagree, is that when I take the OP's question into consideration "What's next after Dynamic Server Meshing", I believe that the number of systems won't really matter.
Or put it in another way, the number of solar systems does not walk in parallel with the "Dynamic" part of the tech.
We can still, theoretically, have any given number of systems, while using the v1 of Server meshins, which will be the Static Server meshing.
So, as I see it, and in accordance to the OP's question, it doesn't really matter if we have just one system, or 20 or 50... We don't really need more than one to test (or at least initial tests) the tech.
Obviously, CIG will give us more than one system, but my point is, Server Meshing doesn't really need more than one system to be tested.