If they do things like they have for the last few expansions, neither raids, neither ranked pvp, neither mythic+ will be available in the first 2 weeks or more.
Realistically you will have more than enough time to level a character to max, maybe even two.
It still doesn’t make it right, or acceptable, but it’s more than enough to bash Blizzard for being greedy.
I think the last time realm first achievements were a thing (for anything other than raids) was in Lich king, but I might be mistaken.
Since I wrote my previous comment, I thought about it, and there are advantages for starting earlier. Reaching max level gives you access to world quests, which can be a source of gear and reputation. It also leaves you more time to complete the weekly objectives before the next reset. If I recall correctly, last time (the launch of Dragonflight) you got an item you can use to increase the power of a piece of crafted gear.
For the average player it doesn’t really matter, but for the world first racers, it might.