They released the R movie in 2004 with a redub and were planning to release a redubbed first season, but the license block by Naoko back then screwed them and the money they invested on it. It was being produced in Rome (unlike the classic dub, which was done in Milan) and a lot of actresses who voice characters in Winx Club were involved. Chibiusa was voiced in the R movie by the same actress who voices Bloom.
Apparently, now that Naoko is in full control and distribution rights are harder and more expensive to negotiate, most countries can't afford for redubs if the classic ones are available. It's the same as asking to lose money. Dynit from Italy mentioned they wished to redub the show with original names and all, but the home video release wouldn't pay itself if they did that.
Crystal's Italian dub ended up being made in Rome instead of Milan as well, but they went with a third voice cast.