Okay, so you don't get the buttery flavour, but you do get a lovely, creamy-smooth, milky white sauce which ... and continuously with a balloon whisk until the sauce has thickened to a smooth ...
Let us tell you a secret, no matter big or small the cafe is, if they have white sauce pasta on their menu, it is almost always safe to go for it. And if they cannot do pasta right, well then, it is ...