I have a theory... When they started producing the MY, this CV-19 pandemic was ramping up, shut downs were happening, and I think there were supply chain issues, so they installed HW 2.5 whenever needed to build a non-FSD order. There are also reports of LR AWD builds being equipped with the performance motor, as evidenced by the VIN number, which also points towards parts shortages and using whatever they had to build more cars to meet demand and end of Q numbers.
That is certainly plausible.