Are you on the Advantage Plan where you automatically get it each year?  You can sign up for Advantage.  There is a Sign Up Now blue button.......

https://ttlc.intuit.com/community/choosing-a-product/help/what-s-the-advantage-of-turbotax-advantage...

I haven't heard or seen anything about pre-orders yet.  You can sign up for Advantage and then cancel it for 2021 if you want, after you get the 2020 CD in November.  On the Advantage plan you get the CD/Download as soon as it comes out.