No they are not.
That is to say, they have everything that would work for hyacinths. They have the right height, the squat body to save the vase from toppling over once the flower grows, the cup could hold several sizes of bulbs flared the way it is.
But they are not hyacinth vases.
When people then ask, why is it not a hyacinth vase if it would work, the answer of our club people would be: it would work even on a jam jar (the method for poor people in the old days).
If I have to be more specific, the cup was not designed with hyacinths in mind and that is something you would realise if you see a whole collection of the real thing.
Hope I made any sense?
Patricia