Only the first emporer will be 'Augustus'. All emporers from then on will just have the title of 'Caesar', as it was historically.

IIRC, the whole emporer name change thing will be dropped in the next release. This is because Gaivs Julivs Caesar an Gaivs Octavianvs Caesar Avgvstvs, which the names come from, won't be your destroyer of the Republic and first Emporer. The names don't make sense in your own version of an alternate history.