I hear this question a lot. There are some very evolved longbow designs, some show reflex when they are strung, which gives them the "hybrid" look, and others do not.
Performance and shooting qualities cannot be predicted by how a bow looks when strung or unstrung. I know of longbows that show no reflex when strung but can shoot faster than some that do show reflex. And anyway, how fast is fast enough? For some 150 fps is plenty fast.
There are several ways to speed up a longbow that do not entail radical reflex, so trying to define what a hybrid longbow is can be difficult, if not impossible.