The Palisade Owners manual which can be downloaded here:
https://www.hyundaipalisade.com/threads/2020-palisade-owners-manual.252/ includes in section 7 Maintenance says the first oil change is required at 7500 miles or 12 months of normal use. For severe use the first oil change is required at 3750 miles or 6 months. Some people like to have the first oil change sooner but this is not required.
The dealer sent the notice to ensure you think of them when you opt to have your vehicle serviced.
SCHEDULED MAINTENANCE SERVICES
Follow Normal Maintenance Schedule if the vehicle is usually operated where none of the following conditions apply. If any of the following conditions apply, you must follow the Maintenance Under Severe Usage Conditions.
• Repeatedly driving short distances of less than 8 km (5 miles) in nor- mal temperature or less than 16 km (10 miles) in freezing tempera- ture
• Extensive engine idling or low speed driving for long distances
• Driving on rough, dusty, muddy, unpaved, graveled or salt- spread roads
• Driving in areas using salt or other corrosive materials or in very cold weather
• Driving in heavy dust conditions • Driving in heavy traffic area
• Driving on uphill, downhill, or mountain road
• Towing a trailer, or using a camper, or roof rack
• Driving as a patrol car, taxi, other commercial use or vehicle towing
• Driving over 170 km/h (106 mph)
• Frequently driving in stop-and-go conditions.
For additional information or assistance see your authorized HYUNDAI dealer.