Ripoff? Homage? Unrelated? You make the call.
P.S. Amtrak used to call these trains conventional trains, as opposed to Metroliners, and then in the 90s dressed them up as NortheastDirect trains. From there they became Acela Regional trains, and then just Regional. It’s still Amfleet cars behind AEM-7 engines for the most part – so this exercise in marketing has not changed a whole lot.