While we still do not have a precise date, those running on RTX hardware will have a chance to get both ray traced effects from ray tracing as well as get more performance from DLSS. It is unclear if Fortnite will make use of DLSS 2.0 or stick to standard DLSS.
Nvidia and Epic released a neat Fortnite RTX reveal trailer so hopefully, we won't wait long for the ray tracing and DLSS update for Fortnite.