Is the new Justin bieber and chris brown song a theme track?

As an AI language model, I don't have immediate access to real-time information or the ability to analyze music in real-time, so I can't confirm if Justin Bieber and Chris Brown have released a new song together or if it's a theme track.

My information cutoff is September 2021, so I may not have access to the most recent releases or information about the artists' discographies. It's best to check official sources such as the artists' social media accounts, music streaming platforms, or reputable music news websites to confirm if there is a new song and its nature.