While I do love being able to put on my best pirate voice and scream at my victims, I don't know if it's a good idea to have voice chat between crews in the long run.
1. It gives away your location easily, giving players a tactical advantage for using Discord or other alternative voice comm services.
My fiancée and I actually managed to make it to an outpost and sell our loot before a galleon could hunt us down because the voice chat of the enemy crew clued us in to their approach (and you can hear it from a decent range, really). Meanwhile, they couldn't hear us making plans because we're in the same room.
2. It allows you to say whatever you want to other players, and given that you've no real idea who's saying it most of the time, there won't be any repercussions.
Odds are, no one is going to have anything kind to say to each other in these situations. There's a reason TF2, Battlefield, and CoD don't have universal voice chat between players fighting each other.
3. It allows for the forming of "griefing fleets", like this: https://www.youtube.com/watch?v=mMpWcVRODx8
It's only through universal voice chat that anyone is able to do this. Without it, and with no way to signal your intention on the high seas, it would become next to impossible to group up to go after other players.
Again, I like the idea of it, but there are a lot of issues, and most of them have nothing to do with people screaming racial slurs at each other, either.
