The worked example also doesn't follow the stylistic rules that would make it satisfyingly authentic as a variation in the style of Beethoven. To calibrate: if you were to submit it as an exercise for music A-Level in the UK (age 16 pre-university) I don't think you would get a passing mark unless your teacher was feeling particularly generous.
But on the other hand, Classical style is incredibly refined and specific. They could have had much more success producing something following the example of Messiaen, who wrote a specific set of harmonic and rhythmic rules he was going to use for all his compositions which would be relatively easy to encode in a program. ("The technique of my musical language" is the 2-volume book I'm talking about and it's completely amazing btw. He really was an incredibly extraordinary person).
https://www.scribd.com/document/355450046/Messiaen-Olivier-T...