It seems the timing was more of a cover for what they already had planned, or at least not every chance was given. Small features in large apps take months, and big features easily take a year. It didn't seem in good faith IMHO, granted this isn't just AWS at the moment.
Ok, but that's not an excuse right? If your platform is too immature to be effectively stopping/mitigating child porn from being published, you don't get the chance to say "yeah but it'll take a while to write the code". They always had the option to shut down while they fix the problem.