Tesla has been plagued with production issues for their current Model 3 production line, so investors were unsurprisingly a bit worried that the Model Y would have similar issues. Musk did his best to assure shareholders that Tesla had learned from the Model 3 and wouldn't make the same mistakes.
The company estimates that the cost and complexity of the Model Y production line will be substantially lower than the Model 3 line. They predict this will result in a faster production ramp up. This is because Model Y will share about 3/4 of the components from the Model 3. Since production methods for those components have already been figured out and optimized, there is less room for error or delays.
The Model 3 is produced at Tesla's Fremont plant in California, while the Model Y will likely be produced at the Nevada Gigafactory. While they company has yet to show a prototype of the design, tooling for the new production line will begin this year. The company predicts Model Y sales will be higher than the Model 3 which they believe will allow "the profitability of our business [to] become sustainable positive."
In other news from the investor report, the Model 3 was the best selling luxury vehicle in the US in 2018. They plan to bring the Shanghai Gigafactory online by the end of 2019 to address global markets. The company also posted its first back-to-back profitable quarters in history.