New ultimates are going to revealed on Friday (well more like tomorrow because of timezones)
I think Okuni is highly likely because he's been screwed out of one for the longest time (like seriously what). Heroes as well although Pandora doesn't really need an ult (but she's most likely to get one >_>)
Indra and Vritra still only have 1 ulti. Same with Amaterasu. And Bal, Amon, and Belial. And Gonia + Bonia. Venus and Hades don't have Awoken ultis. Bodin and Rodin have no ultis at all despite how old Bodin is.
Also for non rem, Hera-Is and Goemon are super fucking old but have no ultis while newer dudes like Athena, Beelz, and Satan got some crazy shit. Zeus-Dios as well I guess but fuck him :V
I'm not actually sure how I'd feel if they revealed a new Isis ult. It might end up throwing a wrench into my God Isis team plans if they end up changing her type or elements. Well I suppose it's very unlikely she'll lose her God Type, and also unlikely she'll get anything in general because all of the Egyptians already have 2 ultis now.