Sons supporting hype? That's unnecessary (8)
I believe the answer is:
'that's unnecessary' is the definition.
(similar in meaning)
'sons supporting hype?' is the wordplay.
'sons' becomes 'ss' (genealogical abbreviation for son written twice).
'supporting' is a charade indicator (letters next to each other) (in a down clue, some letters go below others).
'hype?' becomes 'needle' (I can't justify this - if you can you should give a lot more credence to this answer).
'ss' put after 'needle' is 'NEEDLESS'.
Can you help me to learn more?
(Other definitions for needless that I've seen before include "- - to say" , "Unwanted" , "Without reason" , "without provocation?" , "Unneccessary and unwarranted" .)