Yes uploading into AWS is free/cheap. You pay per GB of data downloaded, which is not cheap.
You can see why, from a sales perspective: AWS' customers generally charge their customers for data they download - so they are extracting a % off that. And moreover, it makes migrating away from AWS quite expensive in a lot of circumstances.
It's not disinformation at all, there's a lot of hurdles to this.
In the link you posted, it even says Amazon can't actually tell if you're leaving AWS or not so they're going to charge you the regular rate. You need explicit approval from them to get this 'free' data transfer.
It feels like you are intentionally missing the point. The blog makes it quite clear that the purpose of notifying AWS is so they stop charging you for that specific type of traffic. How else would they know whether the spike is normal production usage, which is billable, or part of a migration effort?
There is nothing in the blog suggesting that this requires approval from some committee or that it is anything more than a simple administrative step. And if AWS were to act differently, you have grounds to point to the official blog post and request that they honor the stated commitment.
You can see why, from a sales perspective: AWS' customers generally charge their customers for data they download - so they are extracting a % off that. And moreover, it makes migrating away from AWS quite expensive in a lot of circumstances.