Though Ayyavazhi developed independently, most Ayyavazhis consider themselves Hindu because of many similarities and shared dharmic faith. Are questions about Ayyavazhi on topic here?
I think question poster is asking because Ayyavazhi do not consider 'vedas in the form it is available today' as canonical/authoritative . it initially acepts vedas, then considers the current version as totally corrupted and then thats why it considers only its own scripture Akilam as the only valid authoritative source available today.
It is difficult to give a clear-cut listing to Ayyavazhi concepts because of the relation the Ayyavazhi scriptures maintains with the Hindu scriptures. Akilam primarily says the central themes of the existing scriptures (that of Hindu) had gone awry by the advent of Vaikundar. It also narrates that Akilam was given to mankind as an alternative because Kaliyan destroyed the original Vedas and Shastras, and at the beginning of Kali Yuga, several additions were given to the previous scriptures by him. Both of these view points give the views of Akilam on Hindu scriptures, and place them as reasons for rejecting them.
Ayyavazhi accepts various incarnations in Hinduism, but necessarily rejects the so-called ' Hindu ' scriptures. It initially accepts Vedas. Later since Kaliyan had bought the Vedas as boon they too lost their substance by the advent of Kaliyan, and so had gone invalid. It also says that he (Kaliyan) had performed several additions and had hidden some of their content. And hence God incarnated as Vaikundar. So for the present age, Akilam is said to be the only 'Book of Perfection' . By this Ayyavazhi rejects all other scriptures and follows only its own. Akilam highly condemns the creation of religions especially exclusivistic religious and theological ideas. It shows them as the foremost Kali mayai (evil of Kali)
NOW, even though Ayyavazhi do not accept currently available form of vedas, they should be considered Hindus, because:
1) they fully consider themselves hindus, and they declare theselves hindus, they do not identify themselves as other religion (like abrahamic faiths etc). see https://en.wikipedia.org/wiki/Ayyavazhi
2) Many non-vedic agama shashtras do not consider vedas as source, and they are still considered as Hindu scriptures and their followers as hindus.
3) Lingayat does not hold vedas as supreme (Lingayat has been recommended by earlier Karnataka state govt. as separate religion, but that has not been accepted by Central govt; hence legally it is still part of hinduism).
4) Sant Mat,Kapalika,Sri Vidya have their own scriptures which they value, and they do not hold Vedas as canonical authority.
5) Mimamsa argued that the Vedas could not have been authored by a deity
6) Even In Gita, Krishna referred that in certain aspect like Moksha, Vedas don't hold supremacy. e.g. BG 2.45.. refer: Do any Hindu scriptures say that Hinduism is not a religion but simply a way of life?