For one of my clients' sites organic traffic, including branded organic traffic seems to have dropped abruptly when the site relaunched. My sense is that there must be an issue with the way universal is tracking organic traffic compared to before they had universal. There's no other explanation for why organic traffic including the keywords "brand" and "brand.com" (not the real URL) would drop exactly when the site relaunched.
With a second site I am looking at I'm seeing exactly the same behavior. In fact, all they did was relaunch on a new domain without changing the site at all. They changed from something like examplewidgets.com to example.com. On exactly the day of launch their branded traffic dropped abruptly despite the fact they still ranked number 1 for their brand and all variations of it. It seems to be a strange coincidence that in two site relaunches, one a redesign on the same domain and one a new domain with the same design, that branded organic traffic would drop literally the day of launch before Google had even had time to rebuild the indices for those branded keywords.
It seems to me that these can't be "genuine" declines in organic traffic if they started happening within hours of the relaunch, before Google even had a chance to update anything in the search engine results pages.
There is a similar question that has been asked in the Google product forums by someone else with no response. Has anyone encountered something similar?