Are you talking about the changes with patch 2.4? When they get rid of myth tomes, they'll take everything you buy with myth now and make it available in some other way. Atma books will probably be bought with soldiery, which will no longer have a weekly cap (though it could be something else).

It's exactly the same as when they went from philo/myth to myth/sol. There's nothing to panic about. Some things will probably end up being a little easier to get, some a little harder. And then everything will probably get a little easier with each patch afterward.