The Milwaukee Eight engine is a larger and more powerful engine that was introduced in Harley-Davidson's touring and Softail models in 2017.
While there have been rumors and speculations about the Sportster line receiving engine upgrades or updates, Harley-Davidson has not provided specific information or a timeline for such changes. It's worth noting that Harley-Davidson periodically updates and refreshes its motorcycle models, so it is possible that changes could be made to the Sportster line in the future.
To stay up-to-date with the latest announcements and developments from Harley-Davidson regarding the Sportster line, I recommend visiting their official website, contacting authorized Harley-Davidson dealerships, or following their official social media channels for any official updates.