2020-06-23 : If a creature is entering the battlefield under your control, consider static abilities to determine whether its power is 4 or greater. Spells, activated abilities, and triggered abilities can't be used to raise the creature's power in time to have Garruk's Uprising's last ability trigger or to lower it in time to stop it from triggering.

2020-06-23 : If you don't control a creature with power 4 or greater immediately after Garruk's Uprising enters the battlefield, its first ability won't trigger. If you don't control one as the ability resolves, you don't draw a card. They don't have to be the same creature both times, however.

2020-06-23 : Once the last ability of Garruk's Uprising has triggered, lowering the power of the creature won't stop you from drawing a card.

2020-06-23 : The first ability of Garruk's Uprising has you draw just one card, no matter how many creatures you control with power 4 or greater.