Change default Client Settings for Software Center to use the new, not old
Currently, the default client settings have an option called "Use the new Software Center" and it defaults to "No".
Replace this option with something that says "Use the deprecated Software Center" and default it to "No".
This would mean the default behavior on new sites would be to use the New software center. Additionally, I would argue that the upgrade should make this change in the Default Client Settings for existing installs (and document the change in the release notes).
New Software Center is on by default for clean installs. When upgrading, prior selection is preserved, or if coming from a release that does not have this option, it is off by default to ensure the Admin has the ability to control the roll out.
Thanks for the feedback!
AdminMark Silvey - ConfigMgr Product Team (Engineering Manager, ConfigMgr, System Center Configuration Manager) commented
Clean installs should already default to new software center, if you are not seeing that please let us know. Old software center was recently added to the end of life list here https://docs.microsoft.com/en-us/sccm/core/plan-design/changes/removed-and-deprecated-features. When it's no longer supported, it won't be on the disk any more and the setting will effectively go away.
Nash Pherson (MVP) commented
Thanks for all the hard work making the new Software Center a much better piece of UI.