It doesn't appear in the letter, but is mentioned in the article. The letter also states that there are "more" policies that need to be defunded.
These policies encompass bans on pride flags, prohibitions on insurance coverage, restrictions on DEI programs, and even the defunding of children’s hospitals that offer gender-affirming care.
Not that I don't believe you, but is there official documentation showing details on the "more policies" mentioned at the end of the letter? I prefer to read policies verbatim.
I can't say where Erin is pulling the pride flags bit from. Ive found this about Florida wanting to ban pride flags from government buildings and schools.