I find it hilarious how all of those vocal retards never used the search feature in the GEN IV Pokedex. That isn't actually arceus any more than that spark is actually rotom, it was the a placeholder for the general shape of Arceus and all 4 legged, Horse/goat necked shaped pokemon. You can see a similar shiloutette sprite among the many different body shape search options in the Sinnoh pokedex.
That leak really reminds me of the fake "Nintendo DS game anti-piracy screen" trend that also began to surface around the same time.
https://youtube.com/watch?v=UAWhqx14aJk
What are you talking about?
The body shape Arceus falls under, and the only one that remotely matches, is 'quadraped', nothing about neck, and that doesn't have a distinct neck at any point in the silhouettes.
People don't think it's a proto-arceus because it's vaguely shaped right. They think it's proto-arceus because it's associated with Arceus' Dex number specifically.
It was probably created specifically based on what they had for Arceus at the time (a quadraped with flowing head adornments) by a spriter as a placeholder for the final design.
And by this point in the design, they're clearly more closely related to the final form than just a silhouette. Protom is a spark with hands, which would later become vaguely arm-like appendages when the design was finalised. The whole reason these slapdash placeholder images seem to exist is to make it so the programmers and testers can tell what the fuck kind of pokemon they're looking at while they're waiting for the final design.
Why bother creating a small set of prototypes to tell some pokemon apart as placeholders? If it's important to tell them apart, how can , 1: How does that help the programming team if pokemon from several trees look the same, 2: is that a significant improvement over a one-size fits all placeholder?
As for the cry discussion, it prompted me to go through the whole set again while I did other things. I realised by so doing that Gen 3-4 were prime time for good cries.