Personally, I would skip this section or link it out somewhere else as advanced reading. It's rare you need it, and you can do it manually otherwise, so it's not a necessary section for learning purposes.
I would break these examples into multiple lines to make it easier for people to read. I don't think you ever explained `&:` right? I wouldn't bother explaining that and just do it the long way, given this is meant as an intro imo.
Yea given a lot of what you're doing is already accessing methods, I would definitely talk about them, at least in basic detail sooner. It's more useful than things like strings, since everything in Ruby you use ends up hitting a method.
The below example would be a good introduction of the `class` method. Otherwise this example is a bit weird since it's also introducing methods. I would consider adding a short section on methods first, then go into objects. Then you can always go into another more advanced section on methods.