One role of this new department will be to help create the most comprehensive digital map of Britain to date.
GovTracker has no evidence of government plans to combine any parts of the HM Land Registry, Ordnance Survey, the Valuation Office Agency, the Hydrographic Office and Geological Survey. Moreover, there were no updates on this project in the 2017 Land Registry report released on 18th July which includes a section about the digital transformation of their services.
Source: Manifesto - Page 82
Reference 1: 2017 land registry report