Why is profile listing date not disclosed on SMERGERS?

Date of listing is not displayed on any profile because deals should be judged purely based on the merit of the business/profile and not based on the duration it is live on the platform. Deal-making is a typically a long drawn process and can take anywhere between a few weeks to a few years. 

You can always Sort by "Recently Listed" on the Business for sale, Investors & Buyers, Franchises tab. In case you get connected with an opportunity that is no longer available, then kindly login to your dashboard and report the issue for that specific introduction.