Nobody can tell you for sure when it will happen, but it seems like it will be at the end of 2021 or at the very beginning of 2022. It will be a new u[date on the 27th of October called Altair. It will be an upgrade of the beacon chain, which will provide easy customer support, minor fixes for incentives, accounting for inactivity leaks for each validator, increasing rigor and cleaning up validator rewards, taking into account simplified state management.