I have written above code and wanted to do some processing on sublist changed event when Session is 'true', I have done this in SCA 2021.1, I wanted to know if the same code will work for SCS with the extension? Could someone please let me know that? Thanks in advanced.

We generally do not recommend using/referencing core modules in SuiteCommerce extensions. So I wouldn't do this.

Ok, What do we have as an alternative for SCS?

I don't think there is a way to do this that is compatible with best practices