I am not sure what you are talking about. If you are referring to the early September sales in the hundreds of shares by a number of top line management, those were programmed sales having to do with estimated taxes related to the vesting of shares by these officers. Moreover, one of the directors acted on his options and acquired stock late in August.
No one has "dumped" any stock. The reality is quite the contrary. My guess is that the top officers of 8x8 are looking for payday that is far and above the stock price of today. Start with $30 per share and go north.
Again all IMO, of course.