We probably could have helped you with the (old) HD problems
I don't think new campaigns or updates concerning content will be made "officially" to HD, probably due to Paradox still owning the IP. But thanks to the modding tools released in this new version of HD, you can make and/or access user content.
Try this: Go to Control Panel>Programs>Turn Windows Features On/Off. Look under "Legacy Components" and make sure DirectPlay is checked.
The update is not at GOG.com; no idea when it might make it over there. If Majesty Gold HD still doesn't work for you under Win10, try this suggestion from another player:
it has become the game I compare all others to, and none have come close to the entertainment I get from Majesty.