There are several different classes of Add-ins, the most popular are COM Add-ins and Web Add-ins. New Outlook for Windows will not be supporting COM Add-ins. We ran a few reports on what COM Add-ins are installed in the SRP environment so we can try to get ahead of this, and one of the COM Add-ins the report identified is this "ProjectWise iDesktop Integration" COM Add-in.
The New Outlook is officially branded as "Outlook for Windows".
"Outlook for Windows" is not an "upgrade" or "version" of the existing Outlook program, it is a brand-new email client. However, Microsoft will eventually be phasing out the classic Outlook and only the "Outlook for Windows" will remain available/supported.
Please make iDesktop Integration for Outlook for Windows made avaiable in the next version of ProjectWise.
Here are a few Microsoft articles about Microsoft not supporting COM Add-ins in New Outlook for Windows if you are interested in more technical information
Migrate from COM add-ins to web add-ins | Microsoft Learn
Develop Outlook add-ins for the new Outlook on Windows - Office Add-ins | Microsoft Learn