Brainiac throughout the years looked mostly like this:
Later other versions look like this:
I don't see why we could go back to the classic green-skinned humanoid Brainiac with only hint of non-humanity being the red diodes on his head. Originally Brainiac was not tied to Krypton with the exception of the bottle city of Kandor storyline --that's the storyline that I do
not want to see in current MOS world. Otherwise I'm fine with a modern update to the classic Brainiac. Hell, that giant Engineer from Ridley Scott's Prometheus would make an excellent template for Brainiac.