Technically, the company is not doing anything wrong.
The 25 days are still there, and the policy of its paying for unused leaves remains.
What has changed is the administration of the leaves, or the timing thereof.
So it is not a clear cut violation.
Madali ma justify.. sabihin lang nila it is in the interest of orderly leave administration in the interest of orderly operations blah blah blah... and tadah!!! they will whip out that Employment Contract with the Fine Print you signed conforme to ... that you accept Company changes of etc etc etc
No benefit was removed, technically. Na postpone lang pag use mo or pag cash- in mo.