The Rock Hall changed their eligibility window from 26 years to 25 years a few years ago back in 2023, That's why The White Stripes were surprisingly nominated that year because of it.
Actually, Beyonce becomes eligible next year, not 2028. so they really have to get Mariah in this year before Beyonce is eligible next year because we all know that she is an easy FYE lock/shoo-in nominee/inductee next year, so they really need to get Mariah in this year before Beyonce becomes eligible next year.