Identical tests on a 10.0 SP 5 and 10.3 machine (Advanced license on each) yield different search results when using 'Add Data From ArcGIS Online'. For each test I opened ArcGIS to a blank map, signed in to ArcGIS Online, and clicked on the 'Add Data From ArcGIS Online' button. Once the ArcGIS Online window is on the screen I click on 'My Data'. The 10.0 results were blank, 0 results, The 10.3 results showed all of the feature services I had published using the 10.3 desktop so that related tables could be used in Collector. If I use the exact name of a feature service in the search I again get 0 results on the 10.0 machine and 1 result on the 10.3 machine.
Can 10.0 see feature services created in a 10.3 environment? If not, why?