Curious if a resolution has been published yet. My org is about to deploy acrobat with this reg setting. Testing hasn't flushed out this issue yet, but not interested in rolling out a broken app either.
The solution for us, since the registry keys still arn't working, is to use the Adobe Cusomization Wizard to create a transform file with the correct settings ( https://www.adobe.com/devnet-docs/acrobatetk/tools/Wizard/index.html ).
So download the new unified enterprise DC ( https://helpx.adobe.com/acrobat/kb/acrobat-dc-downloads.html ), extract it out, then run the customization wizard against it. Check the options you want (disable sign in at the beginning, disable upsell, accept EULA, etc) and generate a transform file (something.mst). Then when you go to install it use a batch file and a command like this:
msiexec.exe /i "\\Server\Share\Adobe DC\AcroPro.msi" PATCH="\\Server\Share\Adobe DC\AcrobatDCx64Upd2500120474.msp" TRANSFORMS="\\Server\Share\Adobe DC\default.mst" /qb
It will silently install, with a progress bar, with your settings you set in the transform. If you don't log in you get Reader, if oyu login you get whatever you are assigned.