Able to control and ride Happy Ghast if harness is replaced with a different item

If you set the Happy Ghast equipment to something other than a harness, you are still able to ride and control it.

For example, this command

/data modify entity @n[type=minecraft:happy_ghast] equipment set value {body:{count:1,id:"wooden_sword"}}

sets it to a wooden sword, but you’re still able to ride the Ghast. The harness texture isn’t applied.