The demigod is trying to escape his fate not offend a god and die. So he spilled the information in hopes that the tree father will uphold his side of the bargain. He is weak so he can only hope that the one who is stronger than him will decide to be honorable. Such is the only option for the weak.
The queen's rising ego took a big hit when the demigod said that he would only speak with the god. Her ego stalled with the realization of her station. Demigod or not, she is still a mortal and cannot compare to a god.
'I am not even a free mortal. Wasn't I a mortal before I met this entity? Now I am a demigod and also a pawn. I have to become a transcendent and break my limits. Only then will I have my destiny in my hands."
The stalled ego began to deflate when she realized that she is a pawn. She has grown stronger but she has also become a pawn. Pawns are expendable. No matter how good it feels to grow stronger, her fate still hangs in a balance. And most importantly, it is within the hands of another.
All of this is because she got the attention of a stronger entity. She would be free and normal had the tree father not come to her but now she is embroiled in a heist to rip off the gods. She may not survive the repercussions of this heist unless she becomes a transcendent. Only then will she transform from a caterpillar into a butterfly. This ant mound is her protective cocoon, she will be able to leave it and explore the world beyond if she becomes a transcendent.
She held on to that dream of a greater future for herself. It is a dream that all the ant queens of the race of Goliath ants have but none have ever achieved.
It is for this dream that she will continue to be a pawn. It's not like she has a choice anyway. She is just like the demigod. They have to please and be useful or they will die.
The demigod finished telling the tree father about the divine weapon.
The tree father said to the demigod. "I will check the authenticity of your information. In the meantime, you will be exempted from donating your flesh."
Then he said to the ant queen, "Treat this demigod well. He doesn't need to be pampered or waited on but he must not be tortured or used as flesh supply for your grubs."
"I'll see to it." She replied.
"What about the issue of the negotiator?" She asked the tree father.
"I have a plan but we don't need to be anxious. Rushing will make us look weak. Let the gods become frustrated. They are more likely to make mistakes that way. They will come to us when they can't take the wait anymore. Don't you need time to finalize your plans for transcendence? You can use the time we have for that."
The queen accepted the decision meekly. Then she got to work giving out orders while the tree father began thinking of important stuff.
'It is a good thing that Helios was able to subdue that Number 1 without killing it. The ant queen was keeping its position a secret from me. I wonder what else she is keeping a secret from me. It wouldn't matter anyway. Things are going well and will remain so. The ant colony's strength has been kept constant and the gods have been given bargaining chips.' The Tree Father thought to himself.
The reserved forces of the queen have been taken from her and given to the queen. Even if she succeeds in making more royal guards, they will take years to mature and many more years to reach significant strength. So the strength of the queen has been kept effectively constant even though she just became a demigod.
There are a lot of reasons to keep the ant queen's strength constant. An increase in strength will put ideas into her head when she gets full of herself. An increase in strength will increase her ego and make her dissatisfied with the position of a pawn. So as long as her power is constant, she will remain manageable and controllable.
The second reason is to make the gods have something that they can exchange with the ant colony. A negotiation needs two willing parties. The queen has something that the gods want and now they have something she wants. This will ensure that this game continues. It is for this reason that Helios didn't kill Number 1. Reducing the strength of the queen will lower her position and might lead to the game ending quickly.
'I have even come across a so-called GodSlayer. I'll see what it is about and wait. All we have to do now is wait for everything to be put in place.'
The job of confirming the weapon falls to him since Helios is under the spotlight right now. He has a lot of plant spirits so confirming the authenticity of the divine weapon will be easy to do. The divine weapon is not needed for Legion's plan but it will be an advantage if it is useful.
The tree father doesn't intend to let the demigod that told him about the god-killing weapon go. He will be put to use in raising new royal guards if the tree father confirms the divine weapon. His reprieve will be short-lived.
If there's no divine weapon and it was all a hoax, the demigod will simply be put to use for flesh donation. His outcome won't change regardless of the situation of the GodSlayer. The authenticity of the divine weapon may not change his fate, but bringing it has bought him the time for his fate to change. He might live but his destiny to serve his betters won't change.