This is less about Silicon Valley than it is about regionally-specific words. It’s also sort of about majorities and minorities.
In Pittsburgh, “yuns” or “yinz” basically means “you guys.” I went looking to see whether people used it online as well as face to face. It was really, really hard to tell, because Google also thought this was a search for the name Yun or Yin — Chinese names. Just based on the demographics (over a billion people in China, versus maybe two million people in the Pittsburgh metropolitan area), I’d bet there’s way more people online with those last names than there are that use “yuns” as the second person plural. But does “yuns” being in the minority mean that it should be hard to find people saying “yuns” to each other online? What if people are looking for others who talk the way they are? A few later results on these pages are from forums where people ask “Is ‘yuns’ an actual word? My grandma used to use it, but I wasn’t ever sure.”
As you can see, it takes a lot of modifiers, but you can eventually dig up a number of “yuns” results a few pages in, and one or two definition hits in the first few results.