your question is service specific (blockchain.info wallet) and as far as i know they keep a record of all your wallets (bitcoin addresses) in your wallet section, you can find it in your account and you can give different names to all of them. so yes even after a year they are all there to use.
k got it
thanks for that info friend
Auto generated new address is called an HD wallet btw. Afaik, coinbase also uses HD wallets and same as there is an option to use an HD wallet in wallets like mycelium and electrum not only blockchain.info wallets.
Those addresses being generated are all linked to one wallet.