I can't answer in general, but I can come up with an example where a plain atomic does not behave as volatile: link to Compiler Explorer.
You see how the three functions simple, volatile and atomic compile down to the exact same assembly on aarch64. However, in main, volatile is the only call that is not optimized away by the compiler. In other words, if you want the compiler to know your store/load has side effects, atomic is not enough. So it's not a matter of what assembly the actual load/store compiles down to, it's about what optimizations the compiler is allowed to do.