An interesting thing about Roobet casino is that online searches reveal mixed results. Some sites mention 2016, while others mention 2019.
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.