Your post is a pernicious and deceitful attempt to legitimize the kufr of the perennialists. Reliance of the traveller came out in the 90's, Shaykh Nuh has since made it abundantly clear that perennialism is kufr. Many people were simply not aware of Nasr's perennialist philosophy in the beginning. Shaykh Nuh Keller has repeatedly cited Imam Nawawi as saying: