Defender being improved is a win situation for everyone, no matter what AV you actually use. It will push the 3rd party vendors to improve their products.
Since the improvement still leaves Defender far behind anything worth considering as a replacement, I highly doubt it's going to ruffle any ones feathers. 
Actually, that's not quite true. In the tests Defender equaled Ahn Labs and Comodo and was just barely behind Eset. It's not "far behind" any more.
I say it's a win for everyone because all the other vendors use Defender as a baseline and also depend on Microsoft in a large degree for new malware reports. Yes, this does include Avast. If the baseline is raised, then all products should improve to keep from falling behind.
