Yes you're correct! Again what is the best approach? Will the performance can be increased?

I have a doubt that standards available to capture the behavior/context of the user at UI level as Machine Learning is done by the set of algorithms. User profiling, context awareness can be standardized and “learned” at a UI level then we can say this is a UI/UX trends. But I just wanted to check how the JS libraries are created for this purpose and if we have any value proposition for UI/UX in ML?

It completely depends on your own interest rather than the work experiences and assignments that you've working on. Try to understand what is most attracting you in person. Start working on your interested technology/domain whenever you had a time. Finally you"ll became a master one day. But keep in mind that everything is dependent on each other.