They're following CIS guidelines, so if you're in a situation where that matters, it's probably a solid starting point for building things you need to have compliant and predictable. Could probably save weeks of effort, depending on the size of the team.
For SSH it's basically a list of default values with a comment saying "change this if you must". Some summary as to what is hardened compared to a stock SSH install would be nice.
The changelogs contain a summary of actions and changes, and full changelogs go into detail.
As for whether they actually harden your servers, that's up for you to decide if you think that CIS actually helps. It certainly does reduce attack surface.
"""The CIS Benchmarks® are prescriptive configuration recommendations for more than 25+ vendor product families. They represent the consensus-based effort of cybersecurity experts globally to help you protect your systems against threats more confidently."""
So, "what does this mean" is "it means you can tender to sell services to people who put CIS obligations in the contract"