You've pretty much got them covered
Wish only appears on the wizard and sorcerer spell list, and the only other classes that can access those spell lists for level 9 spells are the bard through Magical Secrets and the Arcana Domain of the cleric.
The only other way for a character to gain the effect of wish is through Divine Intervention. This cleric feature says:
Imploring your deity’s aid requires you to use your action. Describe the assistance you seek, and roll percentile dice. If you roll a number equal to or lower than your cleric level, your deity intervenes. The DM chooses the nature of the intervention; the effect of any cleric spell or cleric domain spell would be appropriate.
Wish could be chosen as the nature of the intervention (in fact, it can even be a domain spell to Arcana Domain clerics via the Arcane Mastery feature, a distinction explored by this question)