I believe she meant all she said, she knew how dynamis was the solution to defeat Meteion, and that sundered humans could wield it.
Hydaelyn was probably created because we told her how it ends for the ancients in our time.
At first when you tell her about the future, she didn't understand why she would interfer with the summoning of Zodiark.
That means that if we didn't come and tell her what will happen, she would probably have sacrifice herself to Zodiark.
Knowing that the WoL's future exists, gave her hope that if the ancients falls, humanity could still exist and win.
This future was a last ressort solution she had to keep in mind.
From the start, she decide to not alter the timeline too much in comparaison of what we told her.
She did that so she could follow the sundering plan if everything goes badly and try to unite her timeline with ours.
Had she told people in the convocation or for example sundered Emet Selch, our timeline would never have converged.