Does Draven Legend trigger if an enemy unit is removed from the combat with Starcrossed?

Yes, the Draven Legend ability will trigger in this scenario, provided you win the combat.

According to RiftJudge FAQ #721, combat does not end simply because an opponent's unit is moved away from the battlefield. Combat concludes only when both players pass with focus on an empty chain. If you remove the only enemy unit(s) from the battlefield using Star-Crossed, and you still have units of your own present at that battlefield when combat ends, you are considered the winner of that combat.

Draven's legend ability checks for the combat result at the end of the combat phase. Since you have won the combat, the ability will trigger and you will draw a card.

Sequence:

1. Combat: An enemy unit and your unit(s) are participating in combat.
2. Reaction: You play Star-Crossed targeting the enemy unit and one of your units.
3. Resolution: Star-Crossed resolves, returning both units to their owners' hands.
4. Combat Cleanup: Because your units remain at the battlefield (or you simply have units left while the opponent has none) and the opponent's unit was removed, you are determined to be the winner of the combat.
5. Trigger: Draven's legend ability checks the combat result, confirms you have won, and triggers, allowing you to draw a card.

Note: This interpretation is based on the mechanic that combat continues until both players pass focus, as established in FAQ #721. While FAQ #10587 discusses target removal and the failure of secondary effects, the "combat win" check is a state-based determination made at the end of the combat phase, which persists regardless of how the opponent's units were removed.