If it were on my shortlist I'd be looking at it like this:
Increasing the width allows you to recover some of the cutting power you lost by using stock of X thickness. I don't consider stock of 5mm to be thick on a knife of that length, probably ideal, but other factors being equal it certainly loses out to something of only 3mm thick. Widening the blade allows you to meddle with the geometry and offers the opportunity to make it cut like something thinner.
The disadvantages would obviously be with more blade there is more to drag on. More importantly in my opinion is it loses manoeuvrability.
Would I care? Within reason not with a utility knife. If I wanted a Neo-Bushcraft wood carver then I would care. Wide blades tend not to turn as well in cuts as narrow blades. For a utility knife for Bushcraft-proper, with much less emphasis on twig carving or bowl making, the compromise would be worth it to me. There does come a point at which I think blades become too wide and out of proportion to everything else though.