Probably both. Sales of S5 will likely resume, and they'll also likely release S2 upgrades, possibly with a full S6 not too far behind it.
I expect sales to start back today or tomorrow. S-5 and a S-2 upgrade. Not sure if they will sell an s-6.
I looked at the numbers and S2 upgrade makes sense only if it is very cheap, like $600-700.
If S6 is a 4U machine, shipping from China would be prohibitively expensive for what is probably a 2750-2894Th machine at <1100w (S2 limit).