What exactly do you miss out on, going forward its only likely these trucks will be cheaper and more in abundance. If anything its better to wait.
Experience. It's the same reason I'll try out a new language on a throwaway prototype: real experience helps you think more clearly about the future.
PR, or lack thereof, when these ship.
FedEx could be delivering my packages by horse as far as I'm concerned so long as they arrive on time
Except your competition may get a lock on the supply contract because they were early-adopters. Or they figure out how Tesla is doing it, and risk competing with Tesla, outcompeting you.
Companies that don't innovate better be ready to be disrupted.