It won't be available anywhere in previous conversations and it won't be in the library anywhere, since it was sort of mutually agreed that no one would ever talk about him or Laufey. Odin will be making the post on Day 525 and he won't give this information by default, but if someone asks about him, there are a few NPCs around that would tell them everything. I'm planning on having Honir do just that, because he loves Tyr like nobody's business. Haha But no, this information isn't easily available by default.