But I am confused why the announcement thread has just been made, while the bounty has been going on for a long time and has been running for 4 months from June, or I have missed this project

It's been updated, their website been updated too since they will just start the ICO, bounty maybe is for early promotion.
ANN threads are very quiet, when seen from the start of Intrachain sales, it has started, it looks like LAToken is a portal to buy Tokens from Intrachain,
hopefully investors can trust