You wouldn't want to hard-wire the deidentification company's name into the contract between Google and Spirit. Otherwise, if the deident-company happens to go bankrupt or otherwise be unable to do the work then you'd need to re-do the Google-Spirit contract, which would be a massive pain. And you don't want to make "we can sign this with Spirit now" be dependent on "we have first signed the deal with the deident-company". So I think it's reasonable that the contract says "one or more third parties acceptable to or designated by Buyer" rather than being specific here.