IMHO - parrot playing is concerned with "what" is being played, and it's OK in the context of non-improvised music.
If you want to learn improvisation it helps to also investigate "why" - why this particular rhythmic figure (e.g as shown in the OP article), why this chord voicing (e.g. block chords? Quartal harmony? Drop-2?), why this melody (e.g. ascending or descending? Arpeggiating the chords or "playing outside"?) etc etc
Edit: One more thing: it's OK to improvise with the help of something like iReal Pro, but nothing replaces improvising with real humans, find a group of like minded people that would like to play with you
I played a lot of Chopin, especially the Nocturnes, although none to perfection, and other classical music. That gave me a solid background in music theory, I do believe you could learn all the basics from playing Chopin and thinking about the music.
As an aside, music skill (and many other skills) can be divided into Reading and Writing. Reading consists of either actually reading sheet music, or Playing by Ear. Writing is executing what is in your mind. In the context of improvisation, it's coming up with those things to execute in the first place.
To be honest, I am a good Reader, but a poor Writer myself, and still in the beginning of this part of my journey. I love listening to jazz, and playing along, but devising my own melodies is almost beyond the current me. But what's great about music is that every day you practice is one that you get better.
Scales are great -- but before or above that, I would say ear train. It's a secret (literally -- shockingly few musicians know about it given how useful it is) weapon. It only takes 15 minutes a day for a few months to be able to hear a melody and know what's being played (at least in relative terms -- perfect pitch is harder but unnecessary). After that you can literally study by simply listening to music, which is both more rewarding and more enjoyable than practicing patterns.
(Okay, technically a song is a pattern. But it's a really nice one.)
Today's software beats the hell out of the audio tapes I used in the 90s but the ideas are the same: Familiarization, recall, and recognition.
First you familiarize yourself with an interval, by just playing it all over your instrument, listening and singing it.
Then you test your recall: Play a note N, and try to sing N+I (where I is the interval).
Once you know more than one interval, you can also test recognition: Someone else plays an interval (N,N+I) and you try to identify I.
Once you've got the twelve intervals (you can go past the octave but that's pretty easy so basically there are only 12 to learn) you can do similarly for chords. Chords are also easy compared to intervals, though, because they are built up from intervals, so even before you can recognize them all at once, you'll already have the ability to pick them apart note by note to figure out what they are.
Seriously though, you can think of melody and etc as relative parts of a scale as well as intervals between notes. Ear training using scales is simplest and eventually starts to apply to more complicated patterns. Eventually you recognize the intervals and scales even if you are not consciously thinking about the descriptors like 'oh this is a major third interval'
For me the ability to improvise music emerged slowly after doing a lot of playing other things by ear and embellishing songs either from lead sheets or coming up with premeditated variations on pieces I already knew. But that's just how I did it. If improv is your goal then you could probably benefit from doing it in a semi structured format like 12 bar blues, where it can start very simple and you can build up complexity.
