This appears to be a specific build/version label for Altium Designer (2521 build 25). It’s not a standard public Altium release numbering scheme I recognize from general release channels (Altium typically uses year-based versions like Altium Designer 23, 24, 25, etc., with internal build numbers). “Exclusive” suggests this might be:
Who benefits most from this exclusive build? altium designer 2521 build 25 exclusive