The shuffle conjecture for the character of diagonal coinvariants

Fix $n$ and let $\delta_n=(n-1,n-2,\ldots,1,0)$. For a partition $\lambda\subseteq\delta_n$, let $T$ range over semistandard tableaux of skew shape $(\lambda+(1^n))/\lambda$, and let $\operatorname{dinv}(T)$ be the number of d-inversions defined from the diagonals of the tableau. Define

$$D_n(z;q,t)=\sum_{\lambda\subseteq\delta_n}\;\sum_{T\in\operatorname{SSYT}(\lambda+(1^n)/\lambda)}t^{|\delta_n/\lambda|}q^{\operatorname{dinv}(T)}z^T.$$

Here $\nabla$ is the nabla operator on symmetric functions, $e_n$ is the elementary symmetric function, $h_\mu$ is the complete homogeneous symmetric function, and $\langle\,\ \rangle$ is the Hall inner product. The shuffle conjecture. One has

$$\nabla e_n(z)=D_n(z;q,t).$$

Equivalently, for every partition $\mu$,

$$\langle\nabla e_n,h_\mu\rangle=\sum_{\lambda\subseteq\delta_n}\;\sum_{T\in\operatorname{SSYT}(\lambda+(1^n)/\lambda,\mu)}t^{|\delta_n/\lambda|}q^{\operatorname{dinv}(T)}.$$

This gives a tableau formula for the character of the diagonal coinvariant ring. The source presents it as the main conjecture; no resolution is stated in the supplied text.