If you track this process over a long enough time-period, you’ll find plenty of cases where a word’s Meaning has shifted from negative to positive, or vice-versa. For instance, sophisticated was once an insult (meaning ‘dishonest, deceitful’), and complacent was once a compliment (meaning ‘pleasant, obliging’).
Could –ette be making the same kind of journey? It’s not inconceivable, but on balance I don’t think so. Present-day English speakers may not make the old connection with cheap imitation materials, because most of those words have fallen out of use. But –ette remains common in its diminutive sense, so there’s still a basis for younger speakers to deduce that female-referring terms of the form X + ette imply ‘little X’ as well as ‘female X’—and potentially to find that insulting, just as feminists of my generation did.