Perhaps not a Chelsea type striker per se -- not sure what that is tbh -- but Morata is a Conte striker. Conte bought him at Juventus, and he scored for fun until Madrid wanted to poach him back (buy-back clause) when they had no intention of allowing him many starts. He's pacy, strong; he'll hold up the ball and run like a dog. Just the type Conte likes.
Is Morata a better striker than Lukaku? Possibly not. But Conte has a history of utilising players that are not top-class; he likes players that can do a job and that can be relied upon. That's why he likes Asamoah, Giaccherini, Isla, Darmian, Llorente (signed for Juventus) and now Moses and Alonso; they're not world-class players -- some failed in the English Championship -- but he can rely on them to work like dogs and do a job.