- If my opponent Knocks Out my Active Pokemon and I promote my Zapdos to be Active after the attack, do I get the bonus 70 damage for "Thunderous Assault"?
- No. In this scenario you promoted the Zapdos while it was still your opponent's turn. In order to get Thunderous Assault's additional damage it would have to become Active during YOUR turn.
Source:
Team Up FAQ (2019-01-18), TPCi Rules Team (2019-01-31)