It looks like those sites don't know how to make a proper investigation 
AFAIK, Roobet was officially launched in late 2019. Almost around the same time when this thread was created.
It's true that the domain name roobet.com was registered in 2016 but if you check this archived version from 2018 https://web.archive.org/web/20180808191435/http://roobet.com/ you will see that the domain was offered for sale back then.
absolutely-positioned's earliest posts, especially this one, confirms the above.
The forum has amazing detectives who can find information very well. Roobet came to the forum 2 years ago and in early days they did not run big promotion or big signature campaign. Months later, they decided to launch big signature campaign and promotion as well. Life is so fast and now it is two years since their debut in this forum.AFAIK, Roobet was officially launched in late 2019. Almost around the same time when this thread was created.
It's true that the domain name roobet.com was registered in 2016 but if you check this archived version from 2018 https://web.archive.org/web/20180808191435/http://roobet.com/ you will see that the domain was offered for sale back then.
absolutely-positioned's earliest posts, especially this one, confirms the above.
You 're right with Archive, the gambling site does not exist before 2019 if I am correctly understanding. Just domain was registered and offered for sale.