UK NARIC letter seems mandatory for English

Hi friends,

UK NARIC letter seems to be mandatory as per the new application forms released in May 2105 for English language requirement.
I do not understand what difference does it make to HO to bring in this rule other than we pay additional fee in getting that.

Even the main applicant it is mandatory as the option of already evidence provided during initial Visa application was removed.

Following link is UK Gov official site on the allowed evidences. But the application form does not have the option of PBS evidence.

https://www.gov.uk/english-language/degrees-in-english

At this point I am not sure whether a letter from University is mandatory or not.

Any inputs are really helpful to all of us.

AK