What does ḥattā foreground in «جاءني القوم حتى خالد»?

ʿAṭf al-Bayān, Badal and Coordination: Clarifying, Reinforcing and Specifying the Subject

• Khālid as apposition
• Denial of Khālid’s arrival
• Doubt over who arrived
• Extension of the predicate even to Khālid