[fvold]

You can't outgrow your lineage in evolution. We're monkeys. KFC is made of dinosaurs. Anything descended from bacteria would still be bacteria.

[withinboredom]

They would change taxonomy to archea (see MatrixMan’s comment) thus no longer being bacteria.

These are all human issues, the “archea-bacteria” wouldn’t care what we called it, but fun to think about.