The author said:

yes, there were regressions in some use cases of rsync in the 3.4.3 release. I quite deliberately tried to err on the side of fixing security issues for that release, and there were some valid (but unusual) use cases that got caught up in the changes.

So as I said, I don’t think it’s fair to scream at him to work harder. I do think it’s fair to worn people that rsync is having issues with stability. The author claims he knows what he’s doing and it’s all on purpose. You are free to trust him and ignore the whole affair. Other people may prefer to look for alternatives.