While Ron Howard subsequently added his own unique touches to Solo: A Star Wars Story during the remaining weeks of principal photography and the extended reshoots (like reworking the Dryden Vos character), Lord and Miller’s fingerprints are still all over the movie, so them being credited as executive producers seems more than fair.
Phil Lord and Chris Miller revealed their new status on Solo: A Star Wars Story while speaking at the third annual GLAS Animation Festival Friday (via Variety).
Lord and Miller first boarded the Han Solo movie back in July 2015, and by the time they departed the spinoff movie two years later, approximately 75% of the movie had been shot.