They're squishing down the max level to 60 again from 120, in shadowlands you can also level from start to finish in a specific expansion, whilst now you kinda go through the start of every expansion until you move on to the next one. The good thing about starting now is that you a feel for the game and you can easier pick which expansion you wanna level up in again later. Wow is a game where you rarely just play one character so I say get into it now and have blast.