So large stake pools will be more successful than any one individual competing to be slot leader. Since most ADA is held by the developers, will they be acting as a stake pool? In all the material that explains how this will be done, the snapshots of the process feature them at the top of the food chain, so to speak. Simply go to the Cardano Roadmap to see this in the OPEN OUROBOROS DELEGATION section of Shelley. The images are on the right.
Yes, this could happen… but 1. would make no sense for them to NOT stake. 2. We don’t know yet, as a fact, they will create 1 giant pool (as show in the examples from cardanoroadmap)
I suspect they would apply some of these large amounts as votes (delegated staking) in pool projects they see as valuable. In this way they can subsidize groups that are making promising advances to adoption of the Cardano ecosystem. Pools that are purely for RoI would unlikely see foundation support. If their delegation means 100s or 1000s of additional developers and groups would working on Cardano, this would be a wise way to increase value for everyone.