"Perfect" in this case is a qualitative exaggeration bordering on hyperbole.
> At the end of February, a team of computer scientists at Aarhus University posted a paper arguing that if another unproven conjecture is also true, this is indeed the fastest way multiplication can be done.
You don't know what nobody thinks, because there may be a person that thinks just that. This is an active area of research. Anything quicker than O(nlog n) but slower than O(n) is still possible.
> At the end of February, a team of computer scientists at Aarhus University posted a paper arguing that if another unproven conjecture is also true, this is indeed the fastest way multiplication can be done.