Linux desktop marketshare is going up, though it's definitely not huge. Windows 11 is not particularly popular, and very resource-heavy in a time where those same resources are exploding in price. I'd imagine that hardware companies want to hedge their bets a bit and supporting Linux is this manner is pretty safe.

It's worth noting that HP is also one of the bigger hardware vendors and a lot of servers run Linux, so again firmware updates are probably a good thing you support.