Lease partners won't give you 100% of the value of the vehicle up front, especially not with vehicles that have uncertain depreciation because the EV space is so new.

So depending on the margin, Tesla could absolutely be in a position where building an SR+ Model 3 and leasing it is cash flow negative (over the first 180 days, so once suppliers are paid).

But it's unlikely to be worse than leaving the factory idle, so if that's the lever they need to pull for the demand to be there, it's a no brainer. And they can always raise more money at their current lofty valuation, so cashflow negative isn't necessarily the end of the world.