This is silly. Apple publishes their privacy policy. If they were found to be violating it, they would lose business and be liable for expensive lawsuits. And security researchers are extremely good at finding these things. So yes, Apple has a very powerful incentive to tell the truth.

As for the theory of "open source community," see the MyBTGWallet scam. This open source project, recommended by the Bitcoin Gold team, stole $5 million via a single line of code. Being open source isn't much protection really.