Microsoft is changing Cloud PBX to Microsoft Phone system in Microsoft 365.
For more information, follow the provided link to Microsoft:
https://products.office.com/en-us/skype-for-business/cloud-pbx.
Microsoft Teams and Skype for Business Online are coming together.
Teams will evolve as the primary client for intelligent communications in Office 365, replacing the current Skype for Business client over time.
For more info follow the provided link to Microsoft:
https://products.office.com/en-us/microsoft-teams/group-chat-software
https://blogs.office.com/en-us/2017/09/25/a-new-vision-for-intelligent-communications-in-office-365/