My mother is studying under an Imam (I'm unsure of his aqeedah), and he teaches Tafsir of the Quran weekly in the order it was revealed (I'm also unsure if he's referencing a specific Tafsir book). Is teaching in the order it was revealed a Bidah or makruh?

Ustadh AbdulAziz al-Haqqan

1st time i hear about this and how does he know each ayah and surah chronologically?