Firstly, we're very sorry for this inconvenience. We contacted all subscribers with details of how to access their courses, but with the vagaries of email, our message may have not reached you. Please contact Richard Chesterwood at his LinkedIn page and he will try to help.
It is possible that more courses might be released from one or both of us in future, but we can't promise this.
YES. The K8s and Istio courses are still maintained and supported. A new edition of each is quietly created every year, and this will continue for the foreseeable future.
Although there is a lot of value in the archive, we feel that with a lack of updates, the material is to old to realistically offer for sale.