Honestly, I can't believe I even have to say this.   DNN seems to have a history of assuming that everyone wants whatever new functionality automatically turned on for them by default.   Auto-enabling new functionality on an existing website is just asking for trouble.   For a new portal, fine.  But you seriously risk breaking something on existing websites.  Just leave it as it was and let the portal admin decide if they want to turn it on.

For example, the new popup functionality.  Don't get me wrong, I love it and plan to make great use it.  But, I have A LOT of portals with custom skins that use the telerik version of the [menuactions] skin object.  That control apparently doesn't like javascript as evidenced by the fact that now anytime you click on something that should result in a popup, you get a nasty message "That object has been moved here" with a hyperlink that goes nowhere. 

Yes, I know I can turn it off.  That was fun, having to go through close to one hundred portals and disable that feature until I have time to either fix the skin object or fix the skins to use the default [menuactions] skin object.

Please, stop doing that.  If ever there is a new function that can be selectively enabled or disabled in either Host Settings or Admin Settings, always always always, leave existing installations as they were and don't risk breaking something.

At the point when different options on a particular feature is not longer supported, then of course, you have to do what must be done and risk breaking the website. However, if the option selector is going to be present, then it would be a much better practice to default the selection to the existing way the feature worked for existing websites..