I took a look in my crystal ball, here goes.
Hard to believe that a smallish company like Stark would invest such a sum based on an ever-changing tariff situation.
Plus if the aim was really to avoid tariff, they'd need to build it in the US because the current tariff situation with Mexico is far from being warranted to last...
Finally the US is a significant market for dirt bikes but building a factory to sell a few thousand MX/EX bikes a year does not make sense. Now we know Stark is expending to street bikes of which the rate of adoption is and will remain much higher in Europe than the US (largest market being Asia, especially India and China) so I don't see this happening.
Or maybe if it has nothing to do with the US and the aim is to sell smaller e bikes to Mexico, Brazil and the like, now we're talking huge market opportunities.