The rationale for each one of them, I guess, falls in the toolings they use in the "Vocational IT, Computing, Robotics and ICT C3 courses in Malta", and if that is so, they may be including any new addition.
I was browsing their page and the thing is that they state which packages come preinstalled (powershell is one of them), and the key, I guess, is that they update that least in each release. There's no apparent way to know what packages are added at what time: the releases announcement page is somewhat manually created, and doesn't match the front page.
That "quality", the fact that the ISO is downloaded from the domain itself instead from the usual AWS region or from GitHub, the lack of a SHA256 or similar to check the integrity, a bit of a research over the name of the author and the fact that his email is a GMail one, and not one from an educational institution... all that makes me think that this is more the case of a student or former student experimenting with Linux, FAI and his classmates...