My take is that, just as with forklifts, PLUG has to drag its customers kicking and screaming into the future. "The 20 fleet tractors will be deployed at current Plug Power customers in North America." This reads to me as if PLUG is going to continue to own the tractors and will, most probably, lease them to their existing customers, until such a time as the customers are convinced hydrogen is the future of logistics, which is when they will be willing to purchase their own.
I'm just happy PLUG didn't have to offer stock warrants to get them to try out the tractors.