Technically I don’t think he does. It is standard practice to do it but I don’t think legally required. Since he does not face reelection in 2028, might just say no.
The Dems will make loud, shrill noises, until he divests. So he’ll divest just to shut them up. Then they’ll make loud, shrill noises about something else, and hopefully he’ll put his foot down about the BS then. At some point, you’ve got to let the toddler scream until he’s worn out.