With mobile algorithm update closing by (21st April) John Muller has confirmed during Webmaster hangouts on 7th April that brand terms are unlikely to be affected even for the sites which aren’t mobile friendly;
“So in general, what happens with these kind of demotions is that we try to demote the sites a little bit and what will happen with a branded query or one where we know it is very navigation is we know that this is a really strong result and even if we demote it slightly it will still be up top. So it’s something where I’d say there is no effect at all on branded queries because there is somehow magically different. It’s just that these sites are often very relevant for these queries and even if they are slightly demoted then it is not going to drop them from page one or drop them, sometime snot even from the first position. So that is something where we don’t treat the brand queries in any way special there, but these pages are really relevant and sometimes even if they are demoted slightly, then there still the top result.”
Source; https://www.seroundtable.com/google-brand-mobile-friendly-algorithm-20115.html
Video source (John Muller 37:53) – https://www.youtube.com/watch?v=ipiV2EH8d-M#t=2273 ” title=”https://www.youtube.com/watch?v=ipiV2EH8d-M#t=2273