TBC Prepatch Boosting capability

I dont understand why the boosts are being held for TBC pre patch. Pallys/Shamans for the other side are barred from boosting, where is the harm allowing players to boost and learn their classes for a bit longer than just the short prepatch?

Feels like a bit of a jebait to let us spend on it, then not let us actually use the boost…

I still hope boost will work for the prepatch otherwise I will clearly not have the time to go to lvl 60 with my Paladin future main …
Why changing this now Blizzard ? Was possible in 2021 and allowed paladin to learn to play their char.