In the data for Patch 2.5.3, new global strings have been discovered that indicate text to speech features will be coming to Burning Crusade Classic.
This feature was added to retail with Patch 9.1 Chains of Domination, offering more accessibility features for players.On the Patch 2.5.3 PTR, the TTS feature has not yet been implemented
NEW TEXT_TO_SPEECH Text To Speech NEW SLASH_TEXTTOSPEECH_MENU menu NEW SLASH_TEXTTOSPEECH_HELP_DEFAULT Restore Text to Speech defaults NEW SLASH_TEXTTOSPEECH_HEL. Read more on wowhead.com