Don't forget this report is for 2022, not 2023. The grant for 2023 might be closer to the 2021 level since they're back in patron tier. I can only speculate on what their interests in Cycles is, but maybe they use Blender for making ads and such.
I'm sure their open source contributions aren't out of charity though. They're getting a return on their investment somehow, even if only in the things they use the projects for. I think the open source work would be a better comparison for their ActivityPub integration either way though.