I feel like this is a correction made if not in bad faith then to muddy the waters. Some states held primary elections, others canceled them, and the incumbent didn't participate in any meaningful way. So yes, many states held 2024 dem primary elections, but not all the states, and the party did not treat it as a legitimate primary.
[1] https://en.m.wikipedia.org/wiki/2024_Democratic_Party_presid...