English Wikipedia asked in an RfC for mapframe to be turned on there. We need to let them know what our plans are—that we are emphasizing only a basic locator service and do not plan to add new features in the foreseeable. Providing they can accept that, providing maps to en.wiki will be a positive development for readers.
We should do the consultation as soon as possible. We should launch the feature some time in April, so as to leave time to deal with any fallout before the Collab Team rolls off this project at the end of June.