There used to be a option to disable bluetooth devices waking a Mac. It was removed a couple years ago. I can kind of understand because this would also prevent a keyboard/mouse waking the Mac, which isn’t ideal. I assume a lot of people were turning this setting off then complaining their Mac won’t wake.
However, if a Macbook is sleeping and closed with no peripherals attached, I can’t see any use case for waking from bluetooth. It doesn’t make sense.
Sleeping but plugged into a monitor, while closed, would be one. For other cases, I suspect it's more about making sure the device(s) can be used almost instantly after waking.
Does seem like it'd be nice if the behavior were something you could toggle, though.