You know, there's a reason why I said: "wait".
Let's all assume those who proposed these theories about "Google let authority sites rank better now" and "Authors of articles need to have credible background or certification to rank better" are true... then, it would have just been one of Google's 200+ factors for ranking websites. How can one new factor, of the 200+ ranking factors, immediately tank your website's rankings into oblivion?
If your ranking seems to have dropped and disappeared into oblivion you just have to wait for Google to re-evaluate everyone's website and finalize everyone's ranking again. Just like the analogy I gave about a secretary re-filing a cabinet of papers - let the secretary finish filing it. Not to mention that the update was only fully rolled up last Wednesday or Thursday... it still takes time for Google to re-evaluate the tens of thousands/hundreds of thousands/millions/billions of websites for each keyword/phrase. And if the above proposed theories are true, your ranking shouldn't have fallen that deep, especially if you have good backlinks, social signals, quality content, .etc.
Now you may think, "No way, Sophie, then why are authority websites linking way better now than before?"
Well, because many money sites, PBNs, and such are making use of the practice of having at least 1 outbound link to an authority website! If so many people are doing this practice, wouldn't this update give them a bigger boost?
Also, how can Google verify if a blogger or author truly has a credible background? Everyone could easily fake it (with photoshop, fake text claims, .etc) unless if Google wants every webmaster to submit their qualifications via WMT to prove their credibility. And wouldn't eHow, WikiHow, and such websites be wiped out instead? Every Tom Dick, and Harry can contribute to eHow, wikihow, and whatever how articles... even QnA websites like Yahoo Answers and Quora. Are these answers deem as "credible" sources? And any practising doctor who's into alternative therapies (e.g: Mercola, Dr Axe, .etc) would be on the front page now. And mind you, Mercola and even Dr Oz have all been warned by FDA to stop their nonsensical claims. So how's Google gonna just scan their website's credentials and let them rank well? Wouldn't this factor just backfire them? If you ask me, it is all the social signals and people linking back to them (backlinks) that are helping these websites to rank better. Another theory I can give is because they backed numerous claims with references (like Wikipedia), that may give rise to your ranking as the article would be deemed as 'credible'. Again, I don't know, we don't know, and no one knows until we try it.
Lastly, remember one member who shared about Google's patent about ranking latency? That is, whatever changes you make to your website wouldn't come into effect immediately; instead, it will take up to several weeks or months for it to come into effect. If this is true, then this algorithm update (think of it as a database refresh) would take several weeks again to fully re-evaluate everyone's websites. That's why I worry for those who make immediate changes to their websites right after seeing negative results, especially when the rollout wasn't even completed yet during that time!
Food for thought (and I'm wondering): this update could also have factors to combat against fake news as the U.S mid-term elections are right around the corner. Maybe that's why some people claim aged websites seem to rank way better than new websites?
I've seen client's website rankings for several keywords went into oblivion. Then came back to where it was; then down multiple pages, then back up again. And sometimes this drastic change occur within just several hours apart! Competitors too. That's why I wouldn't try anything for a period of time since the update was only fully rolled out last Wednesday/Thursday (just 4-5 days ago!).
P.S: It's the weekends, I'm tipsy. The above is just my opinion. Take it as a pinch of salt. Heeee!!!