Actually, it hasn’t been fixed. The issue isn’t just Cloth related. It is physics related in general. Cloth, hair, Niagara particles, physics actors, etc… Cloth certainly performs differently now though in 5.2, but still unexpectedly if using TAA.
ho bad news
I am surprised that over two years later this is still a problem. Physics simulation with movie render queue and temporal sampling just does not work at all. Apparently, there are no work arounds either 
I did hear from a developer on Linkedin couple months ago. They are pretty aware of all these issues. The difficulty has been transforming Unreal into VFX software, while preserving its efficiency as a game engine first and foremost. Which is understandable.
Their recommendation is to cache as many effects as you can, especially as they continue to roll out the ability to cache physics elements in the engine when it comes to TAA. They are going to continue to update features and fix things like this in time.
Baking the physics before they go through TAA definitely seems like the way to go here. In the meantime, using time dilation and comping the motion blur manually in Nuke is working ok.