I noticed that they are no longer available from many countries.
They might be unavailable for various reason. It might be for the restriction from those country. For example many countries does not support gambling so they have restricted those gambling sites to the users of their country. Also, there might have mis match terms and conditions and something else.
Gambling is restricted in my country but still I can access the site and demo. Use vpn or other Internet connection may fix the problem.
It will be a good idea if they include a section where it's mentioned that following countries could not access the services. This will clarify the concept.