This is just speculation, but to me it has the appearance of a company that's trying to diversify its own product portfolio, attract investors and advertisers, and disrupt the status quo for sweeping changes rather than small, incremental changes towards its goals.
On MySpace I was involved with moderating the chat rooms, and on MyYearbook I had a high number of followers. In both cases, staff had contacted me cluing me in ahead of time, telling me what I could or couldn't post because of what advertisers or investors would see, and what changes I had to make to my own behaviour. I recall the atmosphere being a lot like this. Tense. Cold. Office-like. Unfriendly and detached from the community. I was also told that I couldn't share any of that information or I would face punishment.
I've also seen the same from the outside. Tumblr, Blizzard, etc.
While those are one trick ponies, Stack Exchange, Inc. can be thought of as a bit more expansive. It has Jobs and it has Teams. I'd wager that with the new CEO, they want to do the same. Expand, and build more products and services for the tech industry.
That costs money, and repeatedly for decades I've witnessed companies believe that acquisitions, reaching for investors and a more in-depth advertiser program, and product diversification and sales meant the loss of one's soul and warmth to the community that got it there.
Just look at old posts from Stack Overflow, like the infamous HTML Regex answer or funniest code comments post. We're different now. We're in the process of that cold, clinical transformation into the cogs of a machine focused on dollars and the boring inner texts about sales figures from a business textbook. Being bought might be the only thing that could save it.