Can't the same fears be said when some cars eliminated such "normal" things as manual/standard transmissions, spare tires, front grilles, tailfins, wing vents, front bench seats, 8-track/cassette/CD decks, some physical/mechanical buttons in favor of touchscreens, or even gasoline engines? Yet, people are not running away from such vehicles in droves.
Sure, there will be some resistance and griping initially from some people who don't like anything that's different from what they're accustomed to. But sometimes you have to lead people rather than just follow the status quo if you want to effect any change. Is there risk associated with change? Sure, but there's also risk in NOT changing. If you don't take risks, you'll never improve. Time will tell if this particular design change will be accepted and succeed or not. If the vast majority of the Model 3 reservations convert to sales and new orders continue to come in at a rapid rate, its interior and user interface will become the new norm. If it flops, then Tesla will have to modify their interior/UI accordingly.
Anyone who can't accept what's shown after the final reveal or are concerned about what others might think of their future car should consider canceling their current reservation. No one should feel "forced" into buying something they don't like or about which they have to feel apologetic.