A new PvP realm is the perfect opportunity to attract both existing players and newcomers. But it comes with the challenge of convincing people to try the server out, as well as retaining those players. I want to see this realm thrive and not die out long-term like Tel'Abim did back on Turtle WoW. Since we know that pvp realms tend to not be as popular as pve realms in the private server scene, I would like to suggest a couple incentives.
1) Exp. Rates
Similar to what Turtle WoW did, I think increasing the experience rate would go a long way toward making the server more appealing. I would suggest starting with 1.5x XP rates. It's a modest increase that reduces the grind without undermining the Vanilla leveling experience, making it easier for players to jump in and stay engaged.
2) Player Protections (Griefing)
I also think the server should include some protection against PvP abuse and repeated griefing. World PvP is one of the biggest draws of a PvP server, but repeatedly being killed by players who vastly outlevel you isn't meaningful PvP—it's simply frustrating and often drives players away.
My suggestion is:
If you're killed by a player who is more than 5 to 10 levels higher than you, you receive a 30-minute buff that prevents players who are more than 5 to 10 levels above your level from attacking or damaging you.
The buff would immediately disappear if you initiate combat against a player who is more than 5+ levels higher than you, preventing it from being abused while still allowing players to opt back into the risk if they choose.
This wouldn't interfere with fair world PvP between similarly leveled players, nor would it eliminate the danger of leveling on a PvP server. It would simply discourage repeated corpse camping and low-level griefing while preserving the excitement and unpredictability that make PvP servers fun.
I think these two changes together—a modest 1.5x XP rate and a sensible anti-griefing protection system—would make the new PvP server much more inviting without compromising the spirit of Vanilla.