I think on a very basic level these guys taking care of this lion is relatively the same thing as a domestication but would lead to very different results. A lion experiencing and adapting to nothing but humans would pick up different traits than a lion in a more inclusive outdoor multi lion program.

That also goes to question, do I think domestication programs in general are as efficient and productive as they could be? Idunno honestly. Money is the ultimate determining factor in the quality in which this shit would exist at all.

Overall, I do think if people shared my opinion on this subject matter, more money and attention would be appropriated to the right directions, and abuse of animals such as a lion would go down as a result. Less fear, better programs, more money, healthy environment for multiple generations of lions, yeh i dont find it unrealistic at all.

Probably not the answer you wanted but its all good.