This is according to an update Ubisoft posted on its website where the company says that due to an issue they discovered during testing, they will have to delay the release of the multiplayer feature. The company did not offer a new release date for the feature which means that we could be either waiting a very long time, or it could be soon, but either way it is uncertain for now.
According to Ubisoft, “We’ve identified an issue in the PC version that can cause the game to crash for players with certain GPUs. The dev team is working on fixing the issue as quickly as possible and in the meantime, we’ve made the decision to wait to launch the PC version until this is fixed. We will communicate the new launch date as soon as possible.”
In the meantime, the multiplayer feature is expected to be released on the 9th of March for consoles, so console players of the game should keep an eye out for its release.