Yep... you didn't see Yamaha release SA as a free upgrade to the T1, did you...?

Or SA2 as a free upgrade to the T2...

If you want to stay current as to voice technology, Korg usually means that your existing arranger will keep pace for a lot longer than some other brands, which make you buy another arranger to have access to the latest technology.

I agree that Korg have been dragging their feet providing TOTL samples to USE with DNC, but we have heard very little of the new ones so far. Doesn't mean they don't exist, though. Still early days, my friends!