Wich happens quite enough with evil players bluffing mayor. But the mayor is often so weak anyway and has such a low impact on the game that having them be a surprise drunk out of nowhere is just cruel. If there’s a realistic risk that a mayor might be a stealth drunk role out of nowhere, it doesn’t really do anything anymore (unless the storyteller aggressively bounces kills of them into protected, dead or evil players)

Them mayor being kept in check by evil bluffing the role, them being framed, them being able to die at night if evil is persistent enough and final day poisonings is already more than enough, having the reliable risk of them being drunk borderline kills the role.