Abrogated verese within Quran (nasikh mansookh), myth or reality?

Re: Abrogated verese within Quran (nasikh mansookh), myth or reality?

add, ‘for sure’ at the end, plus “but the ilm of Nasikh and Mansookh is not a hidden science”. During the 8 year aalim course, ilm of Nasikh and Manssokh is regularly taught