Hey & welcome!  

As technology improved GT updated the content (better video & audio quality, lighting, etc.).  When the courses were updated GT used the opportunity to have a new instructor teach them to get a variety of approaches for students.  Each of the 3 instructors teaching the Fundamentals have their own teaching style with slightly different approaches to the material.  The idea is to provide a better potential experience for students that have more options.

Virtually all beginner guitar curriculums follow a broad, general path:  simple chords, strumming, single notes, picking, full open chords, progressions, scales, barre chords.  Then you are ready for stylistic specialized concepts & techniques.

Strumming is often done first because it's a wide motion & gets beginners introduced to the mechanics of playing.  Playing single notes (and scales) often comes a little later on guitar because it's a more precise & difficult motion.  Also, many beginner guitarists focus naturally on chords because that's the vast majority of what a guitarist does.  And you can play songs right away!  In fact many hobby guitarists exclusively play chords & songs.

There is some wiggle room in the order that things are taught.  But usually you get some combination of the above list.

GT instructors do not get annoyed if a student skips around.  That's an expected part of the structure.  Explore & find what is of value to you.

I did the first Fundmentals courses.  You might find them of value.

https://www.guitartricks.com/course/guitarfundamentals1v1(discontinued)

https://www.guitartricks.com/course/fundamentals2(discontinued)

Hope that helps!  Please ask more questions if you have them.  Best of success!