why Ncert solutions is not given according to the revised schedule of this chapter?

This is simply because NCERT has not revised its book as per the new syllabus. The latest edition that's available is just the reprint of the last year's edition. Thus, as soon as NCERT issues its textbooks as per the latest revisions, we will update them accordingly. However, you can go through the Grewal solutions which are up-to-date and are as per the latest edition of 2013.