It’s not clear. Metaphysical naturalism insists that there is no design in nature and that nature is all there is.
Science is on the move. It is slowly morphing from observing nature to embodying naturalism.
“It’s quite plausible” is treated as equivalent to evidence, eliding the question of how exactly we come to “consciously believe” anything.
They could just as well say that whatever created horses created unicorns, too.
Cosmologists sense the problem and strive to rescue their multiverse from the nagging demands for evidence.