I did a few simple Google searches to illustrate my point. A search for "us guys" brings up 2.6 million hits. Not bad, seems popular enough. However a Google Search for "you guys" a more common use of the vernacular or colloquialism and you get 460 million results. That is roughly 178 times more common. When people see #usguys their mind first latches on to guys, then us is remaining. Since "us guys" is 178 times less common, they assume its an abbreviation and therefore United States. So to a casual observeror, #usguys looks like United States guys, a xenophobic, gender biased group. It is absolutely not that.
For this reason I support changing the name to something less easily confused as bias. After all, your name is your first line of fire when attracting new customers. #usguys is a brand. Just like you are a brand, and your company's name is a brand. If you wan't to sell hamburgers, you don't name your restaurant Waffle Hut, and if you don't want to limit your membership, you don't use a name that is easily confused as something other than it is. Everything is a brand, treat it like it is.