News Courtesy of seroundtable.com:
DA and Google rankings have absolutely nothing to do with each other. Just because your DA score dropped, it does not mean in any way at all that your Google rankings will drop.
I don’t mind having link metrics – hey tons of tools have them. But for some reason, the way Moz has been marketing it, SEOs took on to DA as a Google internal metric. Moz has said numerous times that it is not a Google metric but people don’t read. So I am not sure who to blame but the situation just makes me sad.
Ryan’s Take 
Search Engine Roundtable’s statement on DA is exactly in line with what MOZ said in their update post. If Google were to use a 3rd party’s metric as a factor in the search algorithm, it would be ripe for abuse. When I think of domain authority I see it as a method of measuring domain influence and popularity. If MOZ were to say the hell with it and list every domain with a DA of 100, would that affect keyword rankings? Absolutely not.
Sure, there would be a lot of confusion. However, since it is their own metric, they are free to tweak it as they see fit. As MOZ describes in their algorithm update post, DA is a predicition of how well one domain outranks another. That doesn’t mean a higher rank of DA for a domain will translate to better keyword rankings of a lower DA competitor’s domain. The key is to understand that generally, this should be the case, but it is not definite.
If you consider that Google’s search algorithm is believed to have over 200 ranking factors, then you’d understand just how difficult anyone other than Google can calculate the influence of a domain. No one but Google knows how much weight each factor holds. Therefore, it’s safe to say that any 3rd party domain metric is relying on the average correlation between said metric and the SERPs.
Interestingly enough, the DA of my niche website jumped up 5 points to match the home page’s Page Authority. As much as I’d like to get excited about this, I know that it is just a recalibration of MOZ’s scale and not some boost due to external factors.
So if your website’s DA went up or down, just relax. Your keyword rankings are probably the same as they were before. That is, unless, Google performed its own algorithm update as they tend to do so multiple times throughout the year.
