It's an eyesore to see the decors not fit the primals. So I went ahead and made my recent primal king stay in his Young Cub stage for the decors I equipped to him to fit correctly. He looks great on his personal page, but his bubble in my den looks AWFUL because it still shows him as an adult with the decor fitting badly.
If the den bubble can match the king page whenever they're a female AND posed, they should match when they're in cub form too.