Those were not good developers; ie, there are some skills they were clearly lacking.
I've lived through the opposite situation as you: management left the company, and we continued to release for the next few months without any management at all.
The key, I think, was that the managers had pushed the decision making down. Everyone took turns being scrum master......so when the next sprint came, we elected a new scrum master and carried on.
Fred Brooks pointed out that with a group of competent programmers, any development methodology can work. The best development methodologies help programmers become self-sufficient (teaching them the skills if they don't have them), instead of trying to micro-manage.