Well the term ‘biotoy’ declare, one way or another, they are bio.
I think the main reason most of us consider them animals is the fact that they can reproduce. Moreover, in a very animalistic way, with great efficiency.
If something, the fact that fluffies can reproduce can be considered as ‘canon’.
It makes them be closer to animals than robots or toys.
The good think about fluffies is that your ideas can fly freely.
As far as I remember, there used to be a background story about fluffies can reproduce, and in such a hyper-effectively is the greed of Hasbio. For them it was a cheaper way of “production”, if fluffies breed very fast and quickly, than create every one of them in a vat.
That’s way they wanted to keep the ones capable of reproduction and sell only the sterilised ones. But, PETA queered their pitch, didn’t they? So, therefore, the hyper-prolific fluffies got into the wild.
An other argument can be for they are animals is that they are 'mix-match creatures. They are not built from the scratch with artificial DNA or whatever sci-fi bioengineering. Or maybe, even this possible in case of fluffies. BUT, most times and in most stories they are just mixture of a lot of different already existing animals. Soooo… they are animals, too.
there are two additional argument with this.
- Very mix-match creatures are not always breeding well. For example Mules. A crossbreed of horse and donkey, both of them are equidae, but they are almost always sterile. Fluffies could turn out sterile, but they didn’t because they are our creations.
It can be an element in a story for example, fluffies can breed only with a specific Hasbio component for breeders.
Or generation by generation, fluffies got lamer and lamer, because of there lousy genetic, or lack of blood refreshing.
- A legal drama kind of story. For example, it was in the Jurassic park novel. Genetically engineered animals can be patented. As the Supreme Court rules on that in favor of Harvard, before or something. Therefore, here is your precedent case. So, Using this Hasbio can claim the rights of its fluffies, and no one else can legally make them.
So they animals, can be animals, but virtually still properties.
And bought products for the owners.
I find this idea interesting.
But let me use my fantasy here. 
There is this picture of Artist-kun. This Bio 3D pinters is awesome, I say.
Fluffies could be built cell by cell, protein by protein, being flesh and blood. Not born or grew.
It an other interesting question. Just because your are meat or bio, makes you animal. You could be plant! Fluffies are closer to plant?
Or you just a plushie made out of squishy meaty stuff?
Maybe, fixed up with some wires and microchips to be a sci-fi toy.
Sure, in this case you could easily tell with a microscope or X-ray it is not a regular animal. Still meat-and-bone.
But it makes me think. 
What about the Fuzzy ponies? How much they are biotoys or animals?