Bueno aquí la fuente de la confirmación:
https://support.rockstargames.com/hc/en-us/articles/204078933-Games-on-Demand-GTA-San-Andreas-Replacing-Xbox-Originals-Version
Question: I noticed that the Xbox Originals version of GTA: San Andreas was removed from Xbox LIVE. When will it become available again?
Answer: GTA: San Andreas on the Xbox Marketplace will be available again for purchase beginning October 26th, 2014, through Games on Demand. This version features 720p resolution, enhanced draw distance, and Achievement support.