The "lock-in" and the lack of ownership/copyright extension for media provided by their service is absolutely a problem, but it's not "servitude". There's a couple of other members of FAANG where the relationship with users is much more like servitude.
You can still redownload things. Nintendo says at some point they'll turn that off, but they haven't said when yet.
Even if you made sure to unregister your phone number and email addresses from iMessage first? You can do this while still using an iPhone to validate that it's worked before you give it up.
You are right, of course. And you can also do it afterwards if you forgot. There is no nefarious plan to void your messages when you change phone.
