Merkulov's homology isomorphism conjecture for the truncated graph complex

Let $\mathrm{G}_n$ be the Kontsevich graph complex, with differential $d$, and let $\mathrm{G}^{\mathrm{Me}}_n=\{\Gamma\in\mathrm{G}_n\mid \pi_5\Gamma=\pi_5d\Gamma=0\}$ be Merkulov's truncated graph complex. Merkulov's conjecture. The inclusion of dg vector spaces

$$\mathrm{G}^{\mathrm{Me}}_n\subset\mathrm{G}_n$$

induces a homology isomorphism

$$H_k(\mathrm{G}^{\mathrm{Me}}_n)\cong H_k(\mathrm{G}_n)$$

for all $n$ and $k$. This asserts that the truncated subcomplex captures the full homology of the graph complex; the supplied text gives no evidence of a resolution.