When Forking Monero on GitHub, the code base becomes a public repository. The benefit of Forking as opposed to cloning into a private repository is that the link to the original code base is maintained. However, this means that information such as the IP Addresses of the Seed Nodes and the Genesis block are publicly available. What are the risks associated with this and can they mitigated?
the link to the original code base is maintained
Depends what you mean by "link". There is a link to the original code that is maintained whether you fork publicly on GitHub or whether you clone to a private repository.
However, it would make it harder to do things like issue pull requests if you have a clone instead of a fork. See https://stackoverflow.com/questions/6286571/are-git-forks-actually-git-clones
I assume you are just experimenting, which is why you don't want the world to know the IP addresses of your personal test nodes. Obviously if you ever release your cryptocurrency to the public for them to use, you will necessarily leak information about the genesis block and seed nodes whether they have the source code or not.
There is only a security risk associated with disclosing the IP addresses of your personal test nodes if you aren't securing your OS properly, if you fail to launch publicly accessible nodes in "--restricted-rpc" mode, or if it turns out that there exists or that you introduce a bug into the node code that allows an exploit. If these are test nodes, then you should just firewall them off so that only you can access them.
There is no risk to people knowing your genesis block, unless perhaps you are scared that someone else is going to start competing with you to mine your cryptocurrency. But you can mitigate that by just creating a fresh genesis block when you're ready to launch your cryptocurrency to the public.