There's a community aspect to this game, and supporting that community is an important part of what WotC does. It isn't just a matter of making a product and putting it out there.
The community exists because the product was worth having a community devoted to it. So long as the product is maintained at that level, the community will remain.
People can and will buy a product even if there is no 'community' to join. (IE no message boards, no Twitter feeds, no 'fan club', no social networking etc.) So long as you have a circle of players to play with, there is no requirement for needing ANY contact with anyone outside that circle.
However... a community usually does not last very long if the product they are there to support isn't actually worth organizing around. If a product sucks, the community eventually dissipates.
If you are a company and worry about the social networking parts before the product you produce... you are putting the cart before the horse and you'll more often than not see a quick death. Worry about making product. The community will eventually show up for it. If you can then spend a little bit of time helping the community along, great. But your primary focus should always be looking at the bottom line and making sure what you're putting out is WORTH the community's time in following you.