Haglund–Haiman–Loehr diagonal-coinvariant Hilbert-series conjecture

Let $\mathsf{PF}_n$ be the set of labeled classical parking functions. For $P\in\mathsf{PF}_n$, let $\mathsf{area}(P)$ be its area statistic and let $\mathsf{dinv}(P)$ be its diagonal inversion statistic. Let $\mathsf{DR}_n$ be the doubly graded diagonal coinvariant ring. Haglund–Haiman–Loehr Hilbert-series conjecture. For all $n>0$,

$$\mathsf{Hilb}_{\mathsf{DR}_n}(q,t)=\sum_{P\in\mathsf{PF}_n}q^{\mathsf{area}(P)}t^{\mathsf{dinv}(P)}.$$

This conjecture gives a combinatorial formula for the doubly graded Hilbert series of diagonal coinvariants; the supplied text does not state its resolution.