We propose a nanophotonic structure that gives high-degree quantum interference (QI) in the spontaneous emission (SE) of a quantum emitter (QE) in conjunction with strong light-matter coupling and non-Markovian dynamics. Specifically, we study the SE dynamics of a three-level V-type QE close to a MoS_2 nanodisk (ND). We combine quantum dynamics calculations with electromagnetic calculations and find reversible population dynamics in the QE, together with high-degree QI created by the ND. A rich population dynamics is obtained, depending on the energy of the QE with respect to the energies of the exciton-polariton resonances of the MoS_2 ND, the distance of the QE from the ND, and the initial state of the QE. Our results have potential applications in emergent quantum technologies.