This addon also needs to be reactivated in the addon_utils.py file in the blender2.8 branch of Blender.
Here are a couple of example files for testing: https://people.sc.fsu.edu/~jburkardt/data/ply/ply.html
I removed the texture support that was implemented here: rBA471370
(it is no official part of the file format; the exporter did not support it; reimplementing it is a bit of a hassle)