Earlier quoted context omitted.
Yes and no, it is "worse" than that. In this particular use (for bolognese or pescatora, amatriciana, etc.) "a/al/alla" means "in the style of", BUT when it is pasta al ragù (al pesto, al pomodoro, etc., i.e. other main ingredients) the "a/al/alla" means "with". And we have also our own exceptions, one says "Pappardelle sul cinghiale" (pappardelle is yet another type of pasta), literally "pappardelle on the hog", BUT…
Never heard "pappardelle sul cinghiale"! Sort of slang, maybe. Mai sentito parlare prima di pappardelle sul cinghiale, è un uso abbastanza dialettale mi sa. Ovviamente non si può non concordare sul ragù. ;)
https://it.wikipedia.org/wiki/Pappardelle_sul_cinghiale
https://books.google.it/books?id=M_vYmUgN3e0C&pg=PA289&lpg=P...
you won't find, in any restaurant or "trattoria" in the area written on a menu "al" cinghiale.
It is typical - I believe - of "pappardelle", they are also sometimes (less common recipes) "sulla lepre" or "sul papero".