Trader llama 'DespawnDelay' tag is active, even when spawned with a spawn egg/commands

Possibly caused by the fixes of MC-151047, MC-143699 and MC-152228, the trader llama's DespawnDelay is active, even when spawned with commands or their own spawn eggs instead of the tag being default to 0 similar to the wandering trader, which it would've prevent the trader llama from despawning. Trying to spawn a trader llama with the DespawnDelay set to 0 in the /summon command causes the llama to despawn. The DespawnDelay tag of a wandering trader that has been spawned with commands or with their spawn egg is always default to 0.

How to reproduce

1. Spawn trader llama (untamed)
2. Run

    /data get entity @e[type=trader_llama,limit=1] DespawnDelay 

   → The trader llama's DepsawnDelay tag is active as it is not default to 0.