I would bet someone is already working on a conversion to a Harley engine.
let us hope
Harley has dropped its Sportster range for Europe. One wonders when or whether it will update its larger engines to comply with regulations in a market where its sales are low.
Bear in mind also that HD currently faces a 25% tariff for imports to the EU, so even if they did have a compatible engine for M3W Mk II, it might not be economical for MMC to use them.