Is it a red flag if a casting call says 'all ethnicities' for a role that's clearly written as one?

Saw a casting call that says 'open ethnicity' but the character description is 'Maria, 25, Latina, first-generation immigrant, speaks Spanish to her mother in several scenes.' If they need someone who speaks Spanish and the character is specifically Latina... why say all ethnicities? Is this just a legal thing or should I read into it?