Many of ico just change on their minds and taking up for giving for their tokens sale to offer other exchanges and making an ieo.
That is because they realize that ICO is not viable anymore, there is only a few percentage of success for ICO now.
Lot of bounties making ieo so its a good decission.
Even if they are adopting the IEO, they still need the bounty hunters to promote the project.
Good project like harmony had bounty even if it was in the Binance Launchpad and it's a guaranteed success if you are in Binance.