That's probably why Zoom is buying them, to double down on security and repair their reputation. They genuinely seem to be putting all their focus on improving security. Seems like a smart buy to me.
There hasn't been enough time since the noise about Zoom's security, for a company to inspect the goods, audit the books, negotiate, draft paperwork, share cocktails and all other stuff that come before announcing an acquisition. Especially in the middle of a disruptive situation. The process must had started many months ago.