uverse transition to directv stream

Hello, I just changed from U-verse TV to DirecTV stream.  In the process, on one of 3 tv remote installs, I got a pop up message about a feature for existing u-verse customers.  Apparently there is a feature, whereby, an existing U-verse customer can transfer existing DVR recordings to the DirecTV stream cloud dvr.  I remember something about using "on demand", but I cannot find any additional information about this feature.  Where can I find out how to do this ?  

In continuing to dig through the information, my best guess is that the advice was to find the item of interest (movie, for example) available "on demand" in the Directv stream guides, then record that item to the could dvr.  But, it appears to me, there is no way available to actually transfer from the existing recordings on the U-verse DVR.  Many items would then be lost such as recordings of ball games, music performances, or even movies that are not shown very often; even on the extensive ATT DirecTV streaming service.  Do I interpret this correctly ?  If so, why would ATT send such a message during install time to get our hopes up to preserve these recordings ?