no, buyback is not a new way to attract investors and there are already many examples of projects that do it that way but still cannot make a big demand in the market. ways like that can be done if the product has attracted a lot of people
but, I feel that it is quite influential. imagine, when you buy at ICO or pre ICO prices, and get a lot of bonuses under normal prices, and they intend to buy back, it will make investors interested. however, this only happens to projects that are truly trusted. it will increase the value and quality of the product, and the price of the token.