Wikipedia says,
When $n=4$ (3 space dimensions plus time), it is (the de Sitter space) a cosmological model for the physical universe; see de Sitter universe.
It appears to me that the statement means that our Universe described by the FRW metric is really a de Sitter Universe. I'm not sure that I correctly interpret the Wikipedia statement because it isn't obvious$^1$ to me how the FRW spacetime is related to the de Sitter spacetime. Moreover,the de Sitter spacetime arises as the maximally symmetric vacuum solution (i.e., for $T_{\mu\nu}=0$) of Einstein's field equations with a positive cosmological constant $\Lambda>0$ while for our Universe is $T_{\mu\nu}\neq 0$. Maybe this comment refers only to a very early universe dominated by $\Lambda$ that looked like de Sitter. I'm not quite sure what it means to convey.
$^1$ A de Sitter space is a submanifold of the Minkowski space described by the hyperboloid of one sheet $-x_0^2+\textbf{x}^2=\alpha^2$ where $\alpha$ is some nonzero constant having the dimension of length.