Yggdrasil is an implementation of a new name-independent routing scheme and functions as an end-to-end encrypted IPv6 network. It shares very similar goals to CJDNS.
Yggdrasil was created in order to build a decentralized routing scheme for mesh networks that can potentially operate at a global scale, motivated in particular by significant performance and scaling issues that were present in cjdns at the time. However, Yggdrasil is not a fork.
No, it is not a goal of the Yggdrasil project to provide anonymity. Direct peers over the Internet will be able to see your IP address and may be able to use this information to determine your location or identity. Multicast-discovered peerings on the same network will typically expose your device MAC address. Other nodes on the network may be able to discern some information about which nodes you are peered with.
If you have peerings to more than one node, your node can potentially route traffic on behalf of other network users. If you have only peerings to a single node, you will typically not route traffic, although you may still handle some occasional protocol messages. Keep this in mind if you are restricted by data usage caps.
See also an earlier post, found here on SN, which shared the github repo for the Yggdrasil Network, but in the comments was the Tweet by the author of this pull request where it was shared:
Why Yggdrasil?
Is Yggdrasil anonymous?
Will my node route traffic on behalf of other nodes?