The purpose was to pick interesting features to talk about and select one language for each feature which is a good exponent for that features. For instance I used Smalltalk to cover image based development: https://erikexplores.substack.com/p/what-makes-smalltalk-uni...

Yet Smalltalk was not the first language supporting image based development. I would pick Julia to talk about multiple dispatch. Likewise Zig is picked not because it is the first doing comptime but because that is a central feature of Zig and it is a language which really puts emphasis on it.