Hi @CuboidLeaf87619,
MSFS only installs the base files. Deluxe and Premium Deluxe is installed via the Content Manager or Market Place (as a bundle).
FAQ on top of this forum:
“Only 2 aircraft in the hangar” - How to install additional content? (First installation or reinstallation) – Microsoft Flight Simulator Support (zendesk.com)
AS ALWAYS:
Remove ALL mods before installing any update or content from official MSFS as they may interfere with it’s core files. After installing, you can move back your mods. If the mods are from the Marketplace, you can leave those as is.