Really glad MS didn't buy Slack. I think they're going to be an amazing big business that will generate a lot of cash and opportunity. Most acquisitions by big businesses, either early or late stage, destroy value. Big biz thinks they can innovate by buying. Smaller biz wants an exit. The innovation exits on acquisition and after earn-out. Both suffer and we all lose what could have been the next Google.
If you have a real low level technology, an acquisition can be a good thing, because the big corp could integrate it some of their products and increase the spreading.
But yeah, if we look at Skype and WhatsApp, it's probably good that Slack didn't get acquired.