I won't say there is some traction on this repo, but still :) I won't be able to maintain this project from now on, so please feel free to take the lead or to look at a fork that might be more up to date, especially concerning the version the Bazel.
When running bazel-bin/external/hchauvin_bazel_coverage_report/report/bin --dest_dir=<dest dir>, whatever files present in the destination directory are deleted. I just ran the script with destination directory as my current working directory, and all files there were deleted. Seems like serious enough a problem to need fixing.