You mentioned "for those ....... looking to remove/take over an Avigilon system, this new capability will ease the transition." The aim of Avigilon in opening up their analytics (and the probable outcome as well) is almost certainly the opposite. By giving people a generous taste of what Avigilon analytics but then only offering the full benefits only on Avigilon VMS, you really are encouraging people to move to Avigilon VMS.
In addition, what they offer now in analytics with Milestone is still better than what many other competitors offer today in terms of performance, which will probably help them sell cameras to customers who will never migrate from Milestone to Avigilon VMS anyway but still want a cameras with good performing built-in analytics (which is still relatively rare). This is a market which they have not been addressing before.