So you’ve actually played it and seen it for yourself? The expansion is quite far away and things can easily change for better or worse.
There are things like the Covenants we will need to see to understand.
The way leveling will work in Shadowlands and the incoming level squish is NOT one of those things. It’s set in stone, they are doing it, because they know if they don’t, they will have problems further down the line (or even with SL itself).
Educate yourself, and stop being a pessimist about this:
https://www.wowhead.com/guides/shadowlands-leveling-changes-level-squish