Imo frontier is too niche and specific, if you know what a frontier model means then it's fine, but if you don't then it's negative/detrimental to the title.
"new" does the same thing and is probably just a better descriptor then frontier
But then you're not acting as a billboard promoting AI. Isn't that partly the point?
if you are on HN and have no idea what "frontier model" would mean maybe it's time you found out.