no one knows for sure about the end of the Oikos project, but judging from the activity of the bounty and the Oikos project site is not a scam, you don't need to panic if there is an additional duration of time because there are many bounty projects like that.
There was no indication from oikos to be a scam project. The team has the right to extend the campaign as long as they were adding more reward to the participants.
Investors are still also actively asking the developer in telegram group too.
Any new projects has right to extend bounty time with or without increasing bounty allocation. As Oikos bounty group news, we don't know yet proper time to finish this bounty when already aded extra 8 weeks. If you remove signature your oldest stake will forfeit. After enter this signature, you can't remove signature. Oikos is getting huge success.