One of my friends is an XLRI alumnus and here is what he had to say about this. Irrespective of any degree, your academic future will be a function of the following.
As far as a difference in your FPM and Ph.D. degree is concerned, it doesn't really matter as of now.
Concerning your curiosity about the FPM program at XLRI, it is a subjective approach of each individual. Hope this helps.