Simple RAW for 5e V: The Disadvantage Strikes Back

[Psyren]

421 comment
I think you misunderstood, I was specifically talking of the spells added by Ravnica & Strixhaven backgrounds. Not the Strixhaven Initiate feat.
But I assume both cases are I need to use spells known to gain access?

The spells added to your list from the background are not automatically known, you must learn them.
The spells added to your list from the Strixhaven Initiate feat that the background also gives you ARE automatically known.