Moving to ES from older RedHat

I'm currently looking at what it'd take to move a couple of servers from 
RedHat 7.2 and 7.3 installations over to ES. The ES release notes say:

"Support for upgrading to Red Hat Enterprise Linux ES from a previous 
version of Red Hat Linux is not included with this product. Refer to the 
following URL for more information:

www.redhat.com/software/rhel/as/"

Well, if there's anything to answer that question at that URL, I 
certainly can't find it. The AS release notes say exactly the same thing 
and point to the same page, for one thing.

Can someone tell me if "support is not included" means "we do not 
support this configuration" or "this product cannot do this"? The 
phrasing is a little unclear.

If it can't be done, then my only real option is to reinstall from 
scratch, correct? That'll be a fun weekend. :-/