I thought it very unusual but it might have made some sense.
Rutherford has been the voice of the franchise since he arrived. Allvin hasn't received much in the way of attention from the press. It makes sense to me if he wants to transition the press attention over to the general manager.
Also, he really did get (rightfully) burned with the way he was so vocal about not having anything to do with hiring Boudreau, thinking he had a shorter deal and thinking his system lacked structure. I could see him wanting to stay out of the limelight, maybe even lacking a bit of confidence but mostly just wanting to find a way to be less vocal. Not being there certainly accomplished it.
It doesn't have to mean he won't be there when he has to be. The team really doesn't need the team president to always be the face of the franchise and in the circumstances perhaps it makes sense for Rutherford to be taking steps to get away from that.
Some speculation which is just that and nothing more-Rutherford came to Vancouver and before long was talking about the need to get younger and cut cap. They haven't done a great job of cutting cap and it may be that he's let his general manager manage or taken direction from the owner and wouldn't have made one or more decisions if he'd been the decider. In that case, with the way he's been excoriated for his Boudreau comments, he might well decide that it didn't make sense to risk him putting his foot in his mouth again and to let the general manager actually answer questions about the management of the team.
Who knows? I'm sure there is some reasoning behind it but guess we could speculate for a long time without ever knowing. I don't think think it is necessarily a bad thing but on that, to quote JB fans who kept saying it for far too long, we'll have to wait and see.