When does the "main story bus" stop rolling?

[Ageofwar]

There is...it's in the Waking Sands...there are like, 3-4 quest givers inside for lv46 - lv49.

This is true but in but these are side quests and have nothing to do with the main story.

in terms of the main story there is a jump in the story quests from 46 to 49 where you are put in an 8 man trial fight.