The bivariate tag is a proper subset of joint-distribution.
I have updated wiki excerpts as follows:
Joint probability distribution of several random variables gives the probability that all of them simultaneously lie in a particular region.
Joint probability distribution of two variables.
Briefly looking at the questions, it seems that most questions in the
[joint-distribution] are actually about bivariate distributions, even though many of them are not tagged with
[bivariate]. Given that, we could consider mapping bivariate$\to$joint-distribution. I do not have strong feelings about this. What do people think?