Well unfortunately no new KLR but Kawasaki did just release a new KLX300. Both a dual sport and super moto version.
I am eagerly awaiting the reviews. If it can comfortably maintain a GPS verified 75 mph, has the ability to adjust the rear sag without removing the shock, and my Sargent seat I had on my KLX250 fits like Cinderella's slipper I might get one next fall.
My 09 with 351 kit tops out at 78 on my GPS. 65 is about all I feel comfortable cruising at. However, I still have stock gearing, another tooth on the CS sprocket may make 70 mph comfortable, but I use mine mostly offroad.
The 300 really doesn't look like it's significantly changed other than a bigger bore. I'd suspect the suspension is about the same and most accessories will fit.
https://www.cyclenews.com/2020/11/article/2021-kawasaki-klx300-and-klx300sm-first-look/
(https://www.cyclenews.com/wp-content/uploads/2020/11/2021-Kawasaki-KLX300-and-KLX300SM-First-Look-klx300-730x548.jpeg)
The Seat Concepts seat off my '09 fitted Klaviator's 2020 KLX250 just fine.
My '12 would do 65 without complaining around here, but at high altitude it was pretty anemic. I sold it when I thought off road riding was done, and even the Sargent seat couldn't be tolerated for long. If I end up buying a new one, I will negotiate the dealer setting the rear static sag as part of the purchase.
I've got first dibs on one. I'll never get around to doing the Bill Blue conversion on my 2006 (great bike for that though). All I am looking for is more grunt on the highway in 6th gear and EFI, other than some tweaks to frame geometry and more cc's, I think it is the same bike.