Hydrogen peroxide is known to react with acetonitrile. The product is peroxyacetimidic acid, which is an oxidant, and will ultimately form acetamide. See Article Kinetics of acetonitrile-assisted oxidation of tertiary amin...
Acetonitrile is an aprotic solvent, which means that it does not contain a hydrogen atom that can act as a proton donor. As a result, acetonitrile is not expected to undergo oxidation during the toluene oxidation reaction using hydrogen peroxide. The role of the acetonitrile is primarily to serve as a solvent to dissolve the reactants and products.
Regarding the possible products of the toluene oxidation reaction using hydrogen peroxide, the main products are benzyl alcohol, benzaldehyde, and benzoic acid.
Hydrogen peroxide may oxidize the acetonitrile, resulting in the formation of acetamide. While a different reaction, this is shown to occur when oxidizing tertiary amines to the N-oxides. See https://pubs.rsc.org/en/content/articlelanding/2001/p2/b102066h