Relating to Mimblewimble and Grin, I’ve come across a couple of recent interesting reads, fresh from the oven:

https://medium.com/dragonfly-research/breaking-mimblewimble-privacy-model-84bcd67bfe52
https://medium.com/grin-mimblewimble/factual-inaccuracies-of-breaking-mimblewimbles-privacy-model-8063371839b9 (counters arguments to the former link).

I don’t really know how much certainty the above articles provide, but it casts some doubt as to exactly how far the anonymity goes. At least if it’s what I was after, I’d keep reading these sort of articles for a few days to get a better idea of the extent.