in my heart i know that helga hufflepuff would have accepted squibs into hogwarts and let them take academic classes like astronomy and magical history. and classes that don’t require wands like potions and broom flying. and even set up an apprenticeship program for them based out of hogsmeade or something, to learn to make wizarding tools and elixirs or nonmagical occupations still found in the wizarding world whether its cooking or making shoes or binding books, anything.
helga hufflepuff said she would accept anyone into hogwarts and treat them just the same. she wasn’t about to turn any student away from her school, she certainly isn’t going to encourage squibs being exiled and erased from the magical community.