Disabling a data source in the developer portal simply removes the option from Human Connect.
Data synchronization will continue for all users that previously connected the source when it was available, and you will continue to receive updated data from the source until the user disconnects it themselves via the 'Health data Sources' modal found in the Invitation link.
If you no longer want to support data from a specific source in your product, you can filter data via the
source attribute on each Human API data object that you receive. However, if you choose to do so, it is a good idea to notify your users of this change to avoid confusion and ensure the best user experience.