I think that it would make sense to have your skills unlocked, especially because the Revenant does not have weapon swap. For such a diverse class, it would really take away from how much fun it is if you only ever have a choice on three things (your weapon, legend 1, and legend 2).
Locked skills would also be rough for PvP in the sense that you could look at a Revenant, see that he’s holding a hammer, and then see in the status effects what legend he’s currently running. There’s no mystery there. In one glance, you can tell his entire skillbar, and in 30 seconds when he swaps legends, you’ll know his entire build.
Even if it is just a limited choice as to which skills, I’m sure any sort of diversity would be welcomed. That being said, Anet knows what they’re doing and I’m super excited for the revenant.