AMD stated that they are aiming for the top of the market, not just gamers. They will absolutely target every potentially profitable segment they can. If they only release quad core CPUs, they will only have SMT and clockspeed for differentiation, which gives them a very weak portfolio and exposes them to excessive risk without offering any worthwhile product for the bulk of the market.
Right now, 6+ cores should be the sweet spot for profit and upgrades. You can bet AMD knows this.