Does a unit get defender status (and Yi's +2 might bonus) when targeted by a spell on a battlefield outside of combat?

Ruling: No, a unit does not have defender status when targeted by a spell outside of combat, so Yi's passive does not apply.

Sequence:

• Defender status is applied when units move to a battlefield where combat is in progress and their controller is the defending player
• OR when combat is initiated at the battlefield they are at and their controller is the defending player
• Outside of these specific scenarios, units do not have defender status

Nuances:

• Being targeted by a spell does not grant defender status, even if the unit is on a battlefield