Perhaps the people at Panasonic decided that they had reached a plateau in keyboard technology and there was no further technology needed that hadn't already been done.

If Panasonic had a thriving keyboard bussiness
They surely wouldn't as you suggest close it simply because " there was no further technology needed" I understand they only closed the music division of their bussiness, which means they continue to improve and invest in all other aspects of their products.

In reality if a bussiness closes it's more than likely because it's not making any money,
simple as that!

Because Yamaha, Roland, Korg etc are still out there making keyboards, it must mean that there instruments were more appealing to the majority of music lovers in general. Maybe other factors would also play a part like sales aftercare, marketing skills, etc but the bottom line has to be not enough people were buying Technics keyboards. Which is a great shame as I agree with you the Kn7000 is brilliant.

I hoped they'd go back into production by now, but there you are, we can but live in hope.

All the best

Peter