I am attempting to plan out how to migrate the user data from PM to DEM on Horizon 7.13 in preparation to moving from Linked Clones to Instant Clones. This is a test environment consisting of Windows 10 20H2. This (How to migrate VMware Persona Management to VMware User Environment Manager (2118056)) article references changing the PM folder redirection policy to the path of the new DEM folder redirection. If I do that then how is the user going to get their data from the original path? I'm missing a key step or am simply too dense to see it.
This is a perfectly valid question, you are not missing a step at all. Folder redirection is a beast just by itself and there can be multiple migration strategies depending on existing environment and target environment.
In this case, to help clarify, the referenced KB is suggesting that you point DEM to the existing folder redirection targets currently defined in the Persona Management GPO. After validating, you will be able to safely turn off the PM GPO successfully.