You are forgetting the only important aspect of this. Pokemon go makes Apple and google a ton of money so they turn a blind eye to it because the are directly profiting from it, that is the only reason they don't disclose egg hatch rates.
Your whole argument is flawed and based on your own opinion not facts.
From Apples app store.
Apps offering “loot boxes” or other mechanisms that provide randomized virtual items for purchase must disclose the odds of receiving each type of item to customers prior to purchase.
Sure there is a free incubator, but premium incubators as well as incense and raid passes are a mechanism that provides randomized virtual items for purchase, and as per the app store guideline Niantic MUST disclose the odds.