Funny I was just looking at this since I just got my 2019 Honda Pilot EX-L 2WD serviced yesterday and they said I needed a synthetic oil. (hence the higher price of oil changes for me....). I checked the service manual and on p. 645 it said
"Recommended Engine Oil Oil is a major contributor to your engine’s performance and longevity. If you drive the vehicle with insufficient or deteriorated oil, the engine may fail or be damaged. Genuine Honda Motor Oil • Premium-grade 0W-20 detergent oil with an API Certification Seal on the container. TUse a Genuine Honda Motor Oil or another commercial engine oil of suitable viscosity for the ambient temperature as shown. ■ Synthetic oil You may also use synthetic motor oil if it is labeled with the API Certification Seal and is the specified viscosity grade."