Can Cyclops/Iceman/Beast use their special power:
to reroll a Blades Claws Fangs roll made by a Wolverine with the X-Men Keyword?

I would argue yes, because it's during the attack. I could be wrong though.

BCF is used during an attack. So long as it is the BCF of a friendly X-Men character (like your Wolverine example), that would be fine.

Thank you! That's what I thought.