If you don't mind telling this story, why did you end up merging them back in? I would have thought that needlessly making microservices is bad but not bad enough to justify merging back.
It kind of depends how well you chose the service boundaries. If you chose well, there's not a huge downside, just a bit of extra overhead. If you chose poorly, it can make it practically impossible to have a reliable app with acceptable performance. If you start out with microservices before you understand the problem space, you are much more likely to choose poorly.
