Well, as someone who has one of those (lol) I can say it's kind of exciting!! But Also don't force it just on any design, I think -- with mine, he's a deity, and at his most primal, original state is primarily just a mass of energy with no real form, so he takes whatever the heck form he wants depending on where he goes.

And like Malli said, shape-shifting has been around for so long as a concept that it's honestly nothing people should get upset over. I mean, even without thinking about the ones I've seen, I thought, "hey, maybe this guy could be some sort of deity and shapeshift" and then it went from there -- it's not a very "unique" concept in the sense that we could really pinpoint one person that started it.

Honestly, the only real issue that I can think of, though, is if later down the line you felt you might want to trade or resell the thing. Logically and to be fair, it would make the most sense to have all forms go with it, but then you run into the chance of the person not wanting more than one species form, and they just scrap the rest -- which would suck. That's really the only complication I can think of.