From what I understand, the cost of "erasure" is really just the cost of replacement. True erasure can't exist in a unitary universe. In the same way, the cost of "allocation" is effectively the cost of replacement too, since our universe is unitary and no information can actually be lost at the fundamental level.

Think virtual memory vs actual memory, forks, copy-on-write mechanics, etc. Are we juggling/managing memory or actually creating any? As far as we know, the universe itself is a reversible quantum supercomputer. There are no erasures and a reversible computer is 100% efficient.

If the formula is correct at all, it should apply to the reverse process of setting bits, not just deletion.