Can a spell being cast via a magic item be considered to be more than one class' spell at the same time? Specifically, items phrased along the lines of "While holding it, you can use an action [...] to cast [a spell] from it", with no ties to a particular class (such as Wand of Magic Missiles, Helm of Teleportation, Wand of Entangle, etc.).
The reason I'm asking this question is it seems like it is possible via an odd interaction quirk of the following rules that I'm aware of, and I wanted to make sure I'm not missing anything:
From the answers over on the question of "What makes a spell being cast considered to be a {class} spell?", the implication is that something is a 'class spell' if it is on that class' spell list.
The multiclass spellcasting rules state "Each spell you know and prepare is associated with one of your classes". However, in an instance where you are a multiclassed character who neither knows nor has prepared the spell from either class, I don't think this rule would apply, removing the limit of being associated with only one class.
My current understanding is that spells cast from magic items can still be considered class spells, as per the answer to "Can a sorcerer spell cast from a magic item trigger a Wild Magic Surge" (plus, they are still on the class' spell list, as mentioned above).
(For a specific application of where this may matter, consider this example: Could a multiclassed 10th level School of Evocation wizard/1st level Wild Magic sorcerer PC benefit from both Empowered Evocation and Wild Magic Surge on a single cast of magic missile from a Wand of Magic Missiles, assuming that they did not pick up magic missile as a spell via either of their classes? Empowered Evocation and Wild Magic Surge care that the spell being cast is a wizard spell and a sorcerer spell, respectively.)