Identification: Name this kalanchoe disease.

My kalanchoe has been growing well after a good blooming season, but has now a weird growth at the top of one of the branches. See photo. Is it gall, from mites?

 

Might be a instance of fasciation: Fasciation - Wikipedia.

 

When the picture is opened in a new window and very highly magnified, they are seen to be clusters of plantlets growing on the leaves. They have perfectly formed tiny leaves.

I also want to add that seen under high magnification, there are some spots of fuzzy white thready mildew growing on some of the other large leaves lower down on the same stem. Perhaps the plantlets are growing because the plant is under stress from the mildew growing on it.

Considering there is mildew growing on the kalanchoe I think it would be advisable to move the kalanchoe away from the vicinity of that phalaenopsis orchid that you presently have near it.