When exposed to heat stress, paniculatas can yellow out leaves at the bottom of the bush. I have not seen them turn golden like that but just brown when they abort the blooms. More water helps. Keep it as evenly moist in the summer as you can.

And I would also expect that heat had everything to do with this :-) Planting anything during a midsummer heat wave and possible drought (depending on your location) can have adverse effects that only compound normal transplant shock. Water does help - long and slow and not too frequently. And some shade during the hottest part of the day might also be helpful.

yeah I was worried about that but it was looking extremely wilty and some leaves were yellowing so I was given advice from a few people to just get it in the ground 🤷. thanks I'll keep an eye on watering it.

also, fwiw, the yellow leaves and brown buds happens before planting. fingers crossed this plant is ok

Water the soil and never the leaves when a finger feels dry or almost dry if inserted to a depth of 4". Water from the crown (where the stems originate from) outwards in all directions. Water enough to get the soil moist at a depth of 8" or so. Depending on your soil ty pe, plant size, weather, etc. , you may need 1.5 to 2 gallons of water.