I'm pretty sure they do continue development (and the devs are very productive from what I've seen): GUI wallets, subaddresses and atomic swaps are all planned for this quarter (plus smart contract testing); and private smart contracts are due to be generally available next quarter. We should also soon see the DERO Foundation set up, the source code released to general availability, and the team beginning to attend conferences and market DERO more widely.

Have a look here for the current state of affairs: https://reddit.com/r/DeroProject/comments/8u8kjm/dero_atlantis_mainnet_officially_released_200x/