I'd rather he get it with the contact. That's the point of being a big WR. Rather have a big WR that creates separation with physicality and strength than one that relies on quickness to do it. Because it's pretty rare to find a 6'5" guy with the coordination, hips, and feet to be quick enough to create separation.
If anything, seeing how physical, strong, and assertive Evans already is at his young age...it makes me want him more. You can work on route running(and you have to with almost any prospect)...you can't teach a guy to be mean and physical. Some guys have it, some don't.