I suspect any response you get will not be a concise or definitive answer. And I don’t have one at all. In fact it may seem as if I am throwing a whole bunch of spanners in the works!
This site has almost ground to a halt. You appear to be the first poster in over a week. (there may have been spam though). There is nothing to stop you sampling the keyboard in private, turning it into a library and learning from it, while you wait for some sort of guidance.
Until then, this;
In the UK, it’s from Chad Valley Toys who’s products are now available exclusively through Argos which is owned by Sainsbury’s;
https://www.ar gos.co.uk/product/3498451 (remove the space between ar gos)
In the US, it’s listed as exclusive to Walmart.
From what I can see, the toy keyboard is still available to purchase.
There appear to be single presets for each instrument with no way to alter them.
The fact that you have asked about it, shows you are aware that there could be legal issues. Add to that the fact that they are both very big hitters in their respective countries (and they actually announced plans to merge the UK arm of Walmart; Asda*, with Sainsbury’s, but that was scuppered last year.
Now you must seek permission or clarity from legal advisors or face the consequence of whatever action they could take if they knew about it. The Argos page for the instrument actually has a “Ask a question” button. You could try that.
*(Asda was sold by Walmart earlier this month – October 2020, but retain a minority stake in the business).