*Etymology - Tirumala means the same in all Dravidian languages and yes Tamil is a dravidian language too... What is the loss if mentioned as Dravidian why does Tamil need special importance ? 
 Specifying the meaning of the Temple is applicable only in Tamil is not fair, one may have to mention, Tamil, Kannada, Teleugu and Malayam also, hence it is easier to mention it as Dravidian language. 

 *Annamacharya is the official Poet of the Temple hence he is mentioned here, he is the only one who composed 36000 Kirtanas all of them exlusively in praise of Lor Venkateswara. Please see Annamacharya . Just because his compositions are in Telugu the Official and local language of Tirumala you cannot remove . 
 There is a unique collection of about 3000 copper plates found in the Temple accidentally, on which the Telugu Sankirtanas of Tallapaka Annamacharya are inscribed. This collection forms a valuable source of material for a historical linguist in Telugu, apart from its importance to musicologists. 

 *You may be seeing Telugu language more than Tamil in the article because it is the official and local language of the Temple, please seeTirumala Tirupati Devasthanams the Official administration Board of the Temple which is part of Govenrment of Andhra Pradesh, it is not part of Tamil Nadu government.