This would actually be much worse than what Oda did for Zoro.
up until wano, we’ve been led to believe Zoro’s lineage is unimportant. We never needed to know about his parents because Oda never made us care.
Luffy is the opposite. His dad is dragon and his grandfather is Garp. Revealing his mom in an SBS not only ruins Luffy’s backstory, but the backstories of his family as well.