Theta-packet Arthur multiplicity formula conjecture

Let $F$ be a number field, let $G$ be an even orthogonal or unitary group over $F$, and let $\psi$ be an elliptic $A$-parameter for $G$. Let $\Pi_\psi^\theta(G)$ be the restricted tensor product of the local theta-packets, let $\mathcal{S}_\psi$ be the component group, and let $\epsilon_\psi\in\widehat{\mathcal{S}_\psi}$ be the canonical sign character. Define

$$\Pi_\psi^\theta(G,\epsilon_\psi)=\\{\pi\in\Pi_\psi^\theta(G)\mid\mathcal{J}_{\psi_F}(\pi)=\epsilon_\psi\\}.$$

Theta-packet Arthur multiplicity conjecture. There is a decomposition

$$L^2_\psi(G)=\bigoplus_{\pi\in\Pi_\psi^\theta(G,\epsilon_\psi)}\pi.$$

This is presented as the ultimate goal of the authors' program: it predicts the automorphic discrete-spectrum decomposition selected by the canonical component-group character, generalizing the expected Arthur multiplicity formula for the theta-packets.