Gain the Winds of Wisdom 50% Experience Buff

Incorrect, sir.

[…] We will soon adjust the behavior of creatures in most dungeons to make it significantly more difficult to endlessly snare and kite enemies. Additionally, we will implement a reduction to group XP earned when there is large disparity between player levels in the same group. […] We plan to roll out these adjustments to Burning Crusade Classic realms at the same time as the Joyous Journeys XP buff.

https://us.forums.blizzard.com/en/wow/t/1267344

They’ve said nothing about Joyous Journeys being attached to pre-patch.

beginning a few weeks before the 3.4.0 Pre-Patch

https://us.forums.blizzard.com/en/wow/t/1267341