You may want to revisit the large number of posts over the last week that are speculating about the pulling of this presentation in the face of a pending deal to be released around the time of the ASM. Obviously speculation, but that is what has been put forth.
Other ideas advanced as well, but many feel something is cooking relative to the poison pill developments.
In my opinion...Possible buyout talks in progress...hence the huge push on the proxy voting. Bidder (Biogen?) does not want new information released to the public so that no other bidders could emerge with higher bids.