There seems to be a noticeable difference with the temporal AA sharpness in 4.13. This was confirmed by setting Temporal Sample count and sharpness with the same settings in a 4.12 project. A side by side comparison reveals the issue. A sharpness setting of 0 seems to be the most revealing.
In the 4.13 project you will see much more aliasing as well as some shaking on hard edges depending on camera angle. (see screenshots)
Both projects look the same.
Head over to the existingAnswerHub thread and let us know what's up.