Depends on what kind of Open World PvP.
If it just the same Game where Players can hit each, no thank you.
Never been a fan of it.

Id like to see something similar to GW2 with sieges and stuff, where players can build there own stronghold with different properties like Defense Tower or Supply Base which gives different Bonuses if Connected with other bases.
Since frontlines, is in my opionion at least, a success and pretty balanced and more importantly really tactical im kind of seeing yoshi being able to do something like that and i know yoshi hates Crafters but building Bases, sieges e.t.c would give Crafters also a role.

I dont see this happening though but id like to see something like this as i really like frontlines.