Not necessarily. Social isolation is caused largely by the privatization of social objects. E.g., when everyone can afford their own barbecue they no longer need to go to the country club or town park to make dinner. If people have less money then theoretically there should be more demand for social objects to be socialized. In practice though even if a society shifts from being more gesellschaft to being more gemeinschaft, there are a few different forms this can take, not all of which would ameliorate the problem.
