With it being green lit, it would be funded and something they've been told to go all in on. If it was on a rockier path they likely would've kept it quieter to see how it was progressing before announcing it. It'll either be Sony fully funding it with Bungie likely having to pay them back, or depending on the team size for it Bungie will be using the money that they have from the layoffs and the revenue stream from their subleasing their studio to fund it/other stuff.