Also, to go back to an earlier statement...
This is where my line of thinking is coming from. A normal primal is "influenced by the desires of their creator" but does not require any one of its summoners to act as a heart. But a much larger, planet-scale primal might need a heart because of its size, in which case the desires of the heart infuse the desires of the primal as a whole – but that still doesn't indicate that the heart
becomes the primal as a hypercharged version of themself. If a small "heartless" primal develops its own mind independent of its summoners, why shouldn't a larger primal be the same?
The personality of the heart might form a strong influence on the primal, but that doesn't have to mean directly becoming them.