World border death message states "suffocated in a wall"

Can confirm in 21w06a.

Video attached.

Can confirm in 21w07a.

Can confirm in 21w11a. Relates to MC-21520.

Can confirm in 21w16a.

Most likely a feature request due to the resolution of MC-21520.

Can confirm in 1.17.1.

Can confirm in 1.18.1.

Here's a code analysis of this issue.

Code Analysis:

The following is based on a decompiled version of Minecraft 1.18.1 using MCP-Reborn.

net.minecraft.world.entity.LivingEntity.java

public abstract class LivingEntity extends Entity {
   ...
   public void baseTick() {
      ...
      if (this.isAlive()) {
         boolean flag = this instanceof Player;
         if (this.isInWall()) {
            this.hurt(DamageSource.IN_WALL, 1.0F);
         } else if (flag && !this.level.getWorldBorder().isWithinBounds(this.getBoundingBox())) {
            double d0 = this.level.getWorldBorder().getDistanceToBorder(this) + this.level.getWorldBorder().getDamageSafeZone();
      if (d0 < 0.0D) {
         double d1 = this.level.getWorldBorder().getDamagePerBlock();
               if (d1 > 0.0D) {
                  this.hurt(DamageSource.IN_WALL, (float)Math.max(1, Mth.floor(-d0 * d1)));
               }
            }
         }
         ...

If we look at the above class, we can see that the damage source of damage dealt to entities when outside of the world border is IN_WALL. This is evident through the following line of code:

this.hurt(DamageSource.IN_WALL, (float)Math.max(1, Mth.floor(-d0 * d1)));

As a result of taking IN_WALL damage, the death message "PLAYER suffocated in a wall" is displayed.

Also likely relates to MC-17019.