Why release classic season in the middle of TBC?

[Onikaroshi-mankrik]

In classic? Yes there is, they connected most of the realms to each other during TBC prepatch maintenance

WoW Classic Era Realm Connections Coming May 18

As we approach the moment when WoW Classic players will make the choice to move on to The Burning Crusade Classic (version 2.5.1) or stick with Classic Era (version 1.13.7), we will be connecting many Classic Era realms during maintenance on Tuesday, May 18. This means that in each region/locale, we will create connected realms among groups of Classic Era PvP realms, or groups of Classic Era Normal realms, or Classic Era RP realms. In this region, we will connect: Anathema, Arcanite Reaper, …