It's most likely just a rumor. There shouldn't be a purpose to it unless their previous VA for Bardiche quit and a female was the first new VA they found...
Anyways, hoping Fate gets a henshin sequence in this movie...But it's not looking very likely.
Will be happy to see her loli-er form, though.
It will be interesting to see which scenes they cut entirely and which they try to shorten...I doubt they're going to keep everything considering the time constraints, and the additional material they plan on adding to it.