I think it has more to do with the closing of the 4th tranche. We know that in order for the deb pricing to remain the same the share price can't be at a premium to the convertible. Thus I maintain the circular argument that the buyer is significant and really has to be to do the kind of spending being talked about. If that news was known there would be no way to keep a lid on the price and the ability to maintain tranche 4 at an attractive price is removed. 

So a conclusion could be that POET was simply running out of time for the required notice. 30days plus 4 business days between the distribution of the information circular with the details we are voting on and the date of the AGM. 

Do  the math.

https://www.computershare.com/ca/en/eguide-planning-mailing-date