Didn’t a recent reddit post and experiment confirms it has nothing to do with dust ( And Heat ) ? And the problem hasn't been fixed after three years suggest no one really knows what the causes were.
If I am reading this correctly, there is absolutely nothing about Battery being better positioned to be easily replaceable. Merely that Apple guidelines now allow Battery to be replaced without changing the top case.
That is Apple stopping all those who had Apple Care to get a new top case with their battery replacement or people getting ( used to ) getting around their Keyboard problem with battery replacement.
