does it mean no one can die? Or is something changing?

Not an admin, but I have an answer for this. Although it is not currently possible for player characters to die in combat, they can still die by flying into a star or black hole.

They can also drop their character. This is not technically death as the character continues to exist as an NPC. However, since NPCs are not cursed with combat immortality, a dropped character can die in combat.

So there are currently two ways to die, one just requires extra steps.