It is correct. Dinner jackets are not suits. Even in times not too long ago, if you were to refer to them as such on the Row or in upper class/aristocratic circles you would be considered a rube. Prince Michael of Kent frequently wears odd dinner/smoking jackets. He knows what he's doing.
There was a period where the vast majority would wear matching fabrics and I agree that it is still best to wear a standard barathea rig matching. But a dinner jacket is not a suit. Perhaps a tuxedo is, if a transatlantic distinction is to be made.
Maybe we're getting stuck on semantics but maybe not. A tuxedo, at origin, was formal evening wear sans tails. It was first worn that way in Tuxedo, NY hence the name. Of course, the tuxedo did not stay that way and many adjustments were made to conform to its more casual style, e.g., buttoning jacket, black tie rather than white tie, etc. One concession that I have never seen nor read about is having mismatched fabrics between the pants and jacket. The tuxedo is a suit.
A smoking jacket, on the other hand, is not a tuxedo. It is just that; a smoking jacket. And, yes, smoking jackets and pants should (maybe must) clash. But a tuxedo and a smoking jacket are not interchangeable either in style nor in occasion. A tuxedo or smoking jacket would look great at a party at home or at the club but a smoking jacket would be a bad option at a city concert.
I will assume that you inferred that I was writing about all evening, semi-formal dress rather than tuxedos. In which case, we agree when we use precise terms.