I in generally normally don’t believe people who work for Google or Google in general since they lie most of the time but I think in here they are telling the truth
One thing I did notice with new sites one of the ones I built a couple of days ago has a very fast index rate so I am thinking maybe the glitch was actually done to try and fix the slow index rate most people are getting so far .
I did hear from other SEO friends many people lost a lot of rankings for example if you were rankings for say 10,000 keywords you may only be rankings for like 100 in extreme cases but I suspect the people affected in a negative way will have there rankings restored naturally fairly quick.
Good rule of the thumb to know when an update or a problem happens in the Search engines to many people it’s best to wait and see what happens before you make changes since if you make them wrong you could make your site rank for a lot fewer keywords and just, in theory, create problems you don’t need or your client does not want.
IF I learn anything more in regards to this the article will be updated sorry if it’s a bit small but overall not a lot to say at the moment from my own research or information I was giving so far.