And that's Lilith's true form. For some reason, during those 14 years that we missed, Lilith awakened and took on her true form and both Lances were used to stop her and Mark 06. Then Gendo cut off her head. That head isn't proof that it's a sequel.
You're saying a
giant Rei Ayanami head, the presence of two separate Liliths, one with the mask from End of Evangelion and one with a different mask altogether,
Besides, how do we know that
that's how Lillith's true form is? I only remember that being how Lilith looked after Rei fused with her. And nobody mentions in Eva 3 seeing Lilith emerge from NERV.