That is an amazing feature that benefits everyone, you really want your users to keep updated for security reasons and guess what happens once users can no longer update due to a lack of free space? Apple ran into this because they insisted on selling 16GB models well past the time that was not enough space. I applaud Google for making the hard choice of less free space, but more timely updates.
Android correctly gets a lot of flack for having a fragmented user base which makes it a security and developing nightmare, if this feature were to become standard it would help everyone.
It should also be noted that they are giving away unlimited cloud storage for photos and videos which makes leaving some free space for updates a lot less painful. You probably won't fill your phone with app binaries, it's the photos and videos that take up lots of space.
