In return for a manufacturer getting a Type Certificate, he effectively surrenders control of being able to vary future maintenance requirements, to the authority which issued that TC.
That is how aviation certification works.
That is why for example Cessna's "requirements" for some lifetime limit on some component are not mandatory (under Part 91). The FAA has the final say on that, instead.
And over decades the US aviation scene has developed in that way.
And it has worked very well. The manufacturers publish a list of stuff, but as it is not mandatory, they have not been exactly restrained in what they throw in.
The problem we have here in Europe is that the gravy train riders in EASA, and in the national CAAs before them, have been taking these manufacturer requirements at face value and enforcing them. The system was not designed to work that way, but these people are too dumb to understand, so they enforce life limits on stuff which has got no inherent degradation mechanism, or which is more likely to fail if messed with than if left alone.