I'd be curious to see fan poll numbers on this. Would a majority of people prefer more inter-divisional games, the same amount, or something else? The first counter-argument in thinking about 8 Habs-Bruins games is always the same - that means 8 against Buffalo too, or whichever other Atlantic team currently happens to suck. And perhaps folks are ok with that, but it has to be considered.
My guess though is it will never happen for one main reason - it would make the league look too provincial and not truly national. And that's bad for business. It would also be seen as a backwards step. On the flip side you could point to playoff TV ratings being down as an example of the downsides of the league being spread too thinly and into too many off-market, non-rivalry areas, but my guess is the NHL is actually still reasonably happy because even though total viewership is down, there are people watching hockey in more places, so your footprint is bigger and your sponsors have a broader, more diverse reach. Combine that with record game attendance league-wide, and I see no solid case for change. In most ways the league has never been healthier.