Replicating what they did with iOS 12.1, Apple has seeded the first beta of MacOS Mojave 10.14.1 the day after the .0 release on Monday. The update, which can be found in Settings>System Update for those with registered devices, likely contains bug fixes and other performance tweaks that did not make it into the initial release.
Apple, as they normally do, did not release any Release Notes with the update so what exactly is contained is not clear from a bug fixing perspective. What it does contain is Group FaceTime which also mimics the iOS 12.1 beta build from last week.
Group FaceTime, as many readers will know, was set to be released with iOS 12 and MacOS Mojave. The feature was pulled about midway through the beta testing cycles on both platforms with Apple citing performance issues with the feature. At the time, Apple indicated they wanted to get the update out prior to the end of this year. Now that it is in the beta builds of both platforms, that seems obtainable.
If your MacBook is not in the beta program, you can join it at this link. Even though this is a “dot” update to MacOS, it is still beta so you could run into issues and bugs if you decide to join. It is not recommended your run this on your daily Mac unless you are willing to take that risk.