In the video, the user is typing 'Thumbs up', and when they get to the first 'u' the keyboard shows a 'u' being pressed but a 'j' is inserted instead. Are you suggesting that, due to the way most people construct sentences, the OS thinks that 'thjmbs' is the most likely word? And then the next time the OS thinks that 'thhmbs' is the most likely word?
Both of the issues you've mentioned are common, and irritating, but if you watch the video you can see that that's not what's happening here. Before any autocorrection or adjustment is being done, the keyboard is registering a 'U' and the OS is inputting a J or H or I or some other nearby letter.
The video also debunks the touchmap discontinuity issues as well, because you can clearly see which key the keyboard is registering; it's not assuming that you meant to press J or it would highlight the J; it's registering a U, highlighting U, and inputting J.
It sounds to me as though you didn't watch the video and just assumed what issue was being discussed; please do watch it, because this is another, relatively new, issue that lots of people have seen and which is far worse and more frustrating than the other legitimate issues you mentioned.