New Teams meeting add-in is missing from outlook

It seems that the "New Teams" is a Microsoft Store app and it does not create a folder in %localappdata%\microsoft, probably because the "New Outlook" is a browser version of Outlook that does not need an addin for Teams integration.
I used the Bulk installer from here - https://learn.microsoft.com/en-us/microsoftteams/msi-deployment#msi-files

Please check your Office version (32 or 64 bit) before downloading or you might download the wrong installer!
I also had to delete the registry key also mentioned in the same article - https://learn.microsoft.com/en-us/microsoftteams/msi-deployment#clean-up-and-redeployment-procedure

If the installer does not start on its own, start it from Program Files\teams installer or Program Files (x86)

I was having the same issue...figured out that to create a TEAMS meeting I now need to go to Home-> New Items - > Teams Meeting

Found out about this the hard way. Teams (installed with machine wide installer) removed itself from 90% of our endpoints. We use Teams frequently, so big changes to Teams are not ideal. Installing NEW Teams worked, but we were lacking the plugin for Teams Meetings in Outlook. Several attempts at correcting the plugin all failed. Solution for us was to instruct users to download Classic Teams from the App Store. This allowed users to switch back to the "Classic Teams" and the Outlook plugin for Teams worked again.

Thanks to some of the posts here, the long term solution is to update Outlook to the NEW Outlook using the toggle in Outlook. It would be nice if Microsoft had prepped us or at least had some sort of warning about where to find your Teams meeting plugin. Maybe this was an afterthought by Microsoft.

As per IT Automagic... I saw this reply this morning and decided to look at my registry. Somehow it matched what you suggested adding, and it the New Teams Meeting option was back in Outlook classic. I'm guessing if you have 365, Microsoft has fixed this issue behind the scenes.

Hi Theo,

I faced the same issue with this today, I noticed that one on a few colleagues although I had gone through registering the dll as per -

Had to run CMD as Admin then

C:\windows\system32\regsvr32.exe /n /i:user "C:\Users%USERNAME%\AppData\Local\Microsoft\TeamsMeetingAddin\1.0.23270.2\x64\Microsoft.Teams.AddinLoader.dll"

But I noticed on some machines that the registry key was missing from Computer\HKEY_CURRENT_USER\SOFTWARE\Microsoft\Office\Outlook\Addins\TeamsAddin.FastConnect

Created a new DWORD key - LoadBehavior and set value to 3.

After which Outlook (Classic) has the option back and old classic teams removed from estate.

Carried out multiple tests on my work machine and working fine. Not sure if this will help.