Both are accepted now, but I'm unsure of how you're able to distinguish between "too large" and "very large" in Portuguese? They have two distinct meanings in English; "very large" doesn't mean they won't fit, but "too large" means they definitely won't fit.
It is possible to distinguish between them in Portuguese, it is the difference between "grandes demais" and "muito grandes". I think the reason "too large" is also accepted for "muito grandes" is because in the spoken language placing emphasis on the word "muito" conveys this meaning as well. That is my reasoning, anyway; see: http://www.duolingo.com/comment/61905