Al-jawab billahi at-taufeeq (the answer with Allah's guidance)
Generally, the very pious servants of Allah Ta'ala have Kashf. The meaning of Kashf is the exposure, unveiling of certain non-visible things to certain people.
However, to believe in the unveiling of the graves of anyone is not a requirement of our beliefs. Whoever makes this practice a Sunnah and a requirement then this is Bid'ah. (Fataawa Uthmani Vol.1 Pg.250)