This has a big upside: I can now MITM any Android app / IOT device without any suspicious set up on the device? (given it'll run on the unupdated OS and that cert revocation is not ON).
This is assuming the CT logs no longer issue SCTs for these CAs. If they do then you just need to the CT dance and publish that certificate there.
Of course this assumes the app/device isn't using certificate pinning.