I saw that post too. You say it has been removed ??
There is no way on Earth an insider as high as the CEO would buy knowing a buyout was possible in the following quarter, or even 6 months. It immediately exposes them to criminal charges from the SEC. They would be acting on material information not yet publicly disseminated.
But I have not yet read all of the headlines for this stock, so perhaps they did leak out a headline weeks or months ago? In which case it would be legal to act on it after the fact.
Having said that, there is still remarkable insider accumulation here from multiple C-level execs. They are acting on other information. It's usually something more mundane, such as they simply see a good train of future orders coming down the pipe for the next quarter and beyond.