Specific synergies are generally worth mentioning if they are an example of a broader trend (eg Highway enjoying cantrip +Buy, so using Market as an example), if they are a 2-Card interaction in the same set (eg Poacher works with Library), or are an interaction so powerful you just have to know about it specifically for competitive play (eg Donate Market Square). We can’t catch everything interesting and cool specifically, and that’s not a great way to teach; we want to teach people the general principles so they can see interactions out of components they haven’t seen together before.