Your completely overlooking that they reference the deal made back in September and the conditions set up when they say the warrants were exchanged for shares at a 1.50 on a 1:1 basis.
Of course they might want to exchange if a buyout was coming for less than $1.50 per share, or really any buyout at all. Not sure what good that would do ADXS however, which is why it doesn't make much sense as the reason for the exchange.