Huh. You're lucky.

I had a flight ATL-FCO-BLQ last summer in Premium Select. The departing flight was delayed and would cause a misconnect. I was told in no uncertain terms (via app notification) that another routing was available in Y, but that if I accepted it, I would NOT receive any refund or compensation. At the last minute I was suddenly auto-rerouted ATL-AMS-BLQ, in Premium Select.

How can that even be legal? "We're downgrading you. Like it or lump it."