DeepOnion died at the moment they stopped the so called airdrop in form of staking and signature campaign. The staking was giving great dividends, but after that it was pointless to own DO.
So, no, DO will never hit ATH again. I would be genuine surprised if it ever pass the $1 mark again.
But the project is still active. Recently I have seen they are planning to implement MimbleWimble too which may really increase their adoption more and more. Their dev team is quite active in github too and regularly contributing to the blockchain.