Probably not, based on the information provided. RoHS is aimed at restricting certain hazardous substances in electronics manufacturing, but optical and filter glass have had exemptions under EU RoHS, including extensions that covered these uses. That makes it unlikely that a lens is kept manual-focus purely to avoid RoHS issues with optical glass.

A more plausible reason is technical and business-related: autofocus lenses need electronic communication and mechanical/electronic integration with the camera body, and third-party makers may not have full official interface specifications from camera manufacturers. Producing a manual-focus lens avoids that complexity and compatibility risk.

So while the regulatory concern is understandable, the available evidence points more toward autofocus integration challenges than RoHS avoidance as the reason some lenses are offered only in manual-focus versions.