Doubt it. In the past beta 1-3 were always around the 2 weeks mark. It won't be any different this time around. I also highly doubt beta 1 will be made public, it will be beta 2 or beta 3.
My prediction, iOS 10 Beta 2 for devs will drop around the 27/28th June.
Every 2 weeks makes sense, jumped on the Sierra band wagon too soon
IOS 10 on 5S is running fine, music app has frozen up a couple of times, wifi disconnects etc.

