I'm not familiar with Godot or if the things mentioned in the post have any real merit but reading it as an outsider it's at least not obviously nonsense.
Maybe not fraud or owed anything in the legal sense but does seem crappy if they wasted the money.
Reading Juan's twitter it does seem like the $8M is for W4 games and is not an extension of the Godot project. I still do think it's a bit sketchy that project leaders make a company revolving around their open source project, and then ask for money separately for the project instead of using the funding they got.
EDIT: After a bit of checking, W4 games does seem like they fund Godot as highest tier sponsor: https://fund.godotengine.org/ Which means they must be using their seed fund. The author is probably angry without properly researching things.
"""
W4 Games is a new company created by Godot Engine veterans Juan Linietsky, Rémi Verschelde and Fabio Alessandrelli, and veteran entrepreneur Nicola Farronato.
Our mission is to strengthen the open source Godot ecosystem by providing companies with the commercial products and services they need.
...
W4 Games intends to play an active role in strengthening and professionalizing the Godot ecosystem while remaining as just another citizen of the community, as we believe that Open Source works best when individuals and companies benefit from each other’s contributions on a level playing field. This way, everybody wins and the project benefits as a whole.
We pledge that all the improvements made to Godot as part of the company’s activities will be donated back (whenever legally possible) to the community as pull requests to be reviewed and considered for inclusion.
Additionally, W4 Games pledges to support Godot financially with no-strings-attached donations to the project.
"""
Especially that last part.
Looks like they do donate: https://fund.godotengine.org/ (W4 games is an icon there as "Platinum Sponsor"). It doesn't say how much but given the amounts in the lower tiers it's probably not entirely insignificant.
So they _are_ actually using their $8M seed fund to fund Godot.
I do wonder if the author of the original post did their research properly. W4 games doesn't need to donate but they do so anyway.
If anyone has right to be upset about how W4 Games is spending its money, it would be the people who gave it that money. But I doubt the VCs are upset, because the money is going to building a company that might return on their investment.
Now of course, anyone who knows startups knows the founders are suddenly going to be way deep managing a company and not have time to do OSS management. There should have been a plan to delegate responsibilities to a dedicated employee or other member of the community. The lack of time to manage the OSS and the appearance of a conflict of interest is not hard to predict here...
I don't know if this is that case, but company's mission is to support Godot ecosystem and if lead maintainer raises millions USD for this and then a few months later says there's no money... it's reasonable to think he pockets it. If he sets the company up so that it's impossible to tell if he pockets it... Another red flag.
If so that would be sus enough that project reputation would be done in my eyes.