Yeah, I noted that as well at the beach the other day. I'd =guess= because Hybrid is designed to manage the ICE and EV in the most optimal way, and that's based on the (assumed) use case. So if you're in 4L, you must be getting ready for some serious s***, so it puts all 470 ft/lbs of torque on deck.
And like you said, you can still hit the Electric [only] mode and tool around in silence while still being in Low.
And like you said, you can still hit the Electric [only] mode and tool around in silence while still being in Low.