The blog post says that they had a microservice architecture, then introduced some common libraries which broke the assumptions of compatibility across versions, forcing mass updates if a common dependency was updated. This is when they realized that they were no longer running a microservice architecture, and fused everything into a proper monolith. I see no contradiction.

See my response to a sibling comment: they did not have "forced" updates and they really ended up with:

  > Eventually, all of them were using different versions of these shared libraries.