There are few researches that you can find easily, even though i never thoroughly read the research and mostly focused on de-anonymization :
https://papers.nips.cc/paper/6735-deanonymization-in-the-bitcoin-p2p-network.pdf
http://orbilu.uni.lu/bitstream/10993/18679/1/Ccsfp614s-biryukovATS.pdf
https://arxiv.org/ftp/arxiv/papers/1510/1510.07782.pdf
https://jonasnick.github.io/papers/thesis.pdf
https://arxiv.org/pdf/1801.07501.pdf
www.blockchainresearchnetwork.org/wp-content/uploads/2018/04/Khalilov-and-Levi-2018-A-Survey-on-Anonymity-and-Privacy-in-Bitcoin-like-.pdf

There are specific research for de-anonymization attempt for CoinJoin and mixing service, even though i couldn't find any. Besides, there are few popular chain analysis services such as https://www.chainalysis.com/.


Maybe more people will have privacy/anonymity (even though Bitcoin is only pseudonymous) concern and they might support on-chain anonymity & scaling solutions such as Schnorr Siganture and MAST.