As you know, the master private key is derived from the seed phrase
what a blond girl mindset. wallet soft doesn't generate words , it generates 32 random bytes . based on this it then makes both key and phrase .
He wasn't wrong in his statement "As you know, the master private key is derived from the seed phrase".
As for your statement, first the wallet generates entropy, it can use 32 random alphanumeric bytes as a base, based on this, it creates the BIP39 recovery phrase and then the normal flow.
https://learnmeabitcoin.com/technical/keys/hd-wallets/mnemonic-seed/yeah it turns out they're literally use words as hash source in bip39. like in brainwallet before. So that what i've told applied to them not to that guy. where my scheme is used in electrum and other wallets like this