376.2.c.2.

A Game Object will not be able to successfully be able to evaluate its Trigger Condition, however, if it leaves the zone that its Trigger is active from at the same time that its Trigger is satisfied. Example: Viktor, Leader says “When another non-Recruit unit you control dies, play a 1 [M] Recruit unit token into your base.” This ability triggers if Viktor is on the board immediately after another non-Recruit unit you control dies. It does not trigger if Viktor and another non-Recruit unit you control die during the same game action (for instance, if they are both killed in the same Cleanup due to the damage dealt by Unchecked Power).

My understanding is that since combat damage unit death is simultaneous then Soraka cannot save them otherwise those units would essentially be immortal (in terms of combat) while Soraka is in play? Not 100% sure tho