The problem with that, at least from what I have read in articles about the subject, is that both the solar roof as well as the Powerwall as products appear to be worse than what the competition has to offer while also being more expensive, thus severely limiting market appeal.
Quite the opposite of Tesla cars, which are (at least for now) better than what the competition offers and at more attractive prices too.
Solar roof is debatable - it's a very different product than anything else I've seen on the market. You can certainly install traditional panels for less money, but the result is aesthetically and structurally different; for some folks it might be worth the money.
Powerwall is a different story. I'd be very interested to hear what cheaper alternatives you see. In looking through the market, I can't find anything that's even close to competitive.
You can buy either the lithium batteries or the inverter from other people for about what you pay for both of them from Tesla.