According to the latest episode of the Ride The Lightning podcast, Tesla is finally offering factory tours again, but now it's only available if two people buy Teslas using your referral code, and you choose to spend the loot box points on it.
So that's exciting that tours are theoretically available at least, but also frustrating that they're likely out of reach for most of us. (Feel free to DM me if anyone wants my referral code to help me get into a tour (note to moderators: if this isn't allowed, feel free to edit this part out, I'm not certain what the policy is about mentioning referrals)).