They did, but first they rebranded them as Max, thus destroying the incredible name value of HBO. It was renamed back to HBO as part of the spinout IIRC.
My favorite part of that story is that McKinsey both advised WarnerBros Discovery to make that change, and then advised them to change it back, making millions each time. I wish I made that much money being bad at my job.
McKinsey and other management consultants exist to launder decisions made by upper management that management do not want to face consequences for. "It's not my fault, the consultants advised me that was the best option"
You misunderstand their job. They get paid millions to carefully construct a report that supports whatever stupid plan the coke-fueled execs came up with.
March, 1989: Time and Warner announce merger, Paramount launches hostile bid for Time.
January, 1990: Time responds by buying Warner Communications for $14 billion.