I've downloaded MSFS 2020 Deluxe from Microsoft Store for a second time to find out that there is only two planes in my hangar !  Cessna 152 and TBM 930.  What happened ?

From the MSFS official forum 'Known Issues' page:

Quote

“Only 2 aircraft”

Installing the base sim using a different installation folder than the default folder will only download the mandatory content. To install the non-mandatory content, please do the following:

• Step 1: Go to Profile > Content Manager
• Step 2: Select the content you want to see in the sim
• Step 3: Download and install the content you selected
• Step 3: Reboot your computer
• Step 4: Launch Microsoft Flight Simulator

(I'd put in the link, but my posts with links seem to be getting held for moderation today, so if I put it in you probably wouldn't get to see it for a while)