Daeron just levelled up to level 13 and took two new level 7 spells, shadowshield and banishment.
I just tried Banishment out today and I noticed it has not the same description as the Bioware spell.
It has an innate level of 4 and for sorcerors/wizards it is 5. Still, it is a level 7 spell.
The complete description matches dismissal, except for the name. It looks like it is exactly the same as dismissal, but just takes a higher spellslot. Normally it should also work on outsiders.
Banishment was an important spell for Daeron as I saw him. If this is just dismissal and doesn't work on outsiders it's completely useless.
I also noticed that the spell isn't mentioned in the campaign handbook. If this is really just dismissal, I'll have to ask for a relevel.