I don't think he would be doing press conference if he was going to show up to training camp day one. I thibk this is his way of jumping out and controlling the story when he doesn't show up day one.
I agree with this. That way it's out there, people know what it is, and *ideally* the Pens camp can begin without major distractions. (Although the media will still talk about the Crosby-less Pens, blah blah blah.) To just start camp and not have him there with no news given beforehand would qualify as a major distraction and do more damage than good.
Hopefully whatever the news is, he will be able to do what is best for his health. Concussions aren't to be messed with.
My money's on him announcing that he won't be back for training camp, but that he should be back at some point this season. Plus I think he'll just generally answer questions about the recovery process, since this is the first time he'll have spoken publicly since last season.