Heres my thoughts, looking at the bigger scenario.
If you are approached, or have the idea to - create a book that contains exercises to sell and make money, you are going to
a - try and cover 100s of different exercises that haven't been done before to make it look like a comprehensive guide
b - make the hardest and strangest exercises you can in order to make the pianist feel inadequate because if they cannot do them initially then there must be something to learn by studying them, making the book seem better than it necessarily is.
That opinion aside, there are a few points. Firstly it may certainly benefit to learn different fingerings, we often find ourselves, when learning pieces, not always able to use the optimal fingering, and have to accomadate when required, which can feel umcomfortable, if not used to.
And second, it has been stated, that Liszt was known to apply the same initial scale fingering 123/1234/123 etc to every scale, including black key scales, advising that if you can master those, you will no longer feel any discomfort with thumbs on black keys or white inbetween. I imagine he may have had a similar thought process when developing the exercises. Honestly back in his day, his technique was basically second to none, but from his own admission he practiced ALOT.