In the notifications we receive, they often talk about the change being relevant for Elektron_DD or Elektron_AD services, but never for hEDD (which is what we use) or any other Reuters services.
hEDD seems to look stangely like a diminutive of Elektron_DD!
I'm trying to figure out, positively, if the notifications apply to us.
You are correct, depending on the delivery mechanism, Elektron service can be named "hEDD" and "ELEKTRON_DD". In additional, for a deployed installation it can also be aliased with any service name that customer finds convenient (for example, for historical reasons some prefer to call their Elektron service "IDN_RDF") and thereafter the service is referred to by that name.
Any content/data notification that you see, that is applicable to ELEKTRON_DD service, will be applicable to hEDD on EMS hosted. For example, symbology change notification is of interest to many, and it will fully apply.
Service/delivery mechanism notifications will differ, those will be specific to the delivery mechanism.
Hope this helps clarify?