Should not look at things in such a black and white view. Many years ago when Steve Jobs asked Warren Buffett what to do with the cash that Apple was generating. Buffett suggested to buyback Apple shares. Jobs didn't buy back. If he did, AAPL now would be above $2000 a share, instead of $300. Eventually Apple did do large scale share buyback in recent years, but instead of buying at $8~10, they bought back at $100~$200. The late share buyback is still a good move, it would have been much better if they did earlier.
If Tesla is generating $5B free cash a year, and the stock is super cheap from long term view, spending half billion to buy back shares would do wonders. Some people may think stock price has no effect on the business. The effect is huge to the employees, business partners, investors, debt cost, and demand.
For growth, Tesla made it clear that going forward they will copy the Shanghai Gigafactory model. Which means money comes from local banks, factory is constructed in phases, cashflow from first phase will pay for the second and third phases. They will need very little cash from the company.
Sooner or later Tesla will buyback half of the shares.