I think the unsold tokens will be burned by smart contract. This is a general way to deal with the unsold tokens. I hope the softcap can be reached and no much unsold coins will be burned.
The Unsold token will be returned to the company's treasury.
That is not a good way, the investors may worried about these unsold tokens, if the company start to sell these unsold tokens, that will make the price very low and the investors will be panic, I hope the unsold tokens can be burned or just locked for extra selling, much better than just return.