Digimon knew what they were. They've been withholding information.

Furthermore, our 'partners' were given to us by the same force that gave us our Digivices, and that source, I think I've just seen has a definite interest in making sure we're not too powerful. Despite giving us these crests at the same time. We're missing too much information. Digimon could potentially be double-agents, even if they aren't aware.

[She sounds distracted as she talks, and the sound of pencil scratching on paper can be heard as she goes.]