Are Multiclass moves shattering niche protection for casters?

Just really noticed the Multiclass moves and no one has taken one yet in our game. In feading they really seem to steal the spellcasters' thunder though. Does anyone have a character in their game that has picked up Multiclassed spell casting of a caster type that already exists in the group? How's it playing out?

I don't (yet) because folks are enjoying rocking the base casters.  If you read the caster level-up moves it seems not to be just about the spells but about getting them out there (having the stats to go for the full hits) and the moves to back them up (extra d8's of healing, full on damage mitigation, and the wizard is full of goodness).

Multiclass casters seem to 'do well enough' when there are no base casters (particularly because they have moves of their own to fall back on), but I don't think they'll steal the limelight.

I just multiclassed my fighter into wizard and now a wizard has joined the party. I wanted to take non-damaging spells since I can already do good damage. The wizard is taking the ones I didn't take. I think it will work out fine, especially if the wizard researches/creates new spells. Plenty of wide open space for that and my fighter doesn't seem like the type to sit around and run experiments.