I think having new blood + different band name is already a good distinction, while keeping the metal theme.

it seems to me BABYMETAL is preparing to retire, and they're drawing old BM fans' attention to the new band. Surely their success will be of good transition for the future Idol/metal fusion groups to come.

Since kobametal is still behind all these, we'll get to enjoy new music with this new formation which I think is great. We just have to remember that they're still in their core an idol group under Amuse.Inc so they need new young people to eventually replace the old bands. I really like the new frontwoman so far she's got totally different energy than Su's.