Closely held shares and all. At least they might not intend to sell their shares in the normal course. Sell though, they might..... in one transaction....hmmm?
Most likely they are either getting rid of previous investor preferences because it is advantageous as a result of a buyout, or they are getting some new significant financing and the new investor wants the benefit of preferred shares to the detriment of the previous preferred.
I have never seen this actually announced before a buyout. Usually, you’d just convert them all before closing. That makes me lean toward a new, bigger investor, but still just a guess.