No, it is not. “au fait” is needed here.
“initier” can be ‘transitif’ – it is the case here, it takes the meaning “to be taught” ; or ‘intransitif’, it then takes the meaning “to begin”

No, you have to use it.

Initier doesn’t behave like apprendre, it’s closer to introduce (to something), both in meaning and grammar. It’s supposed to be used for a wide subject, not something very precise.

Il m’a initié à la philosophie.

Je suis allé à cours d’initiation au tir à l’arc.

Initier is always transitive, so you always have to use "Initier à". Using au fait que is a workaround to use initier instead of apprendre, to convey the idea of "gently dipping into a subject", but they’re not really synonyms.

In the same way, you can’t say "malgré que" (despite the fact that a lot of people say it), like in English actually: despite must be followed by a noun, so you have to transform your subordinate sentence ("a lot of people say it") to be a noun, and you do that by adding "the fact that".