If you had already been into the MS Store app, and downloaded the update, it will request to install them.
If you have not, MSFS will tell you there are updates to be downloaded from the MS Store first, then close down. You can then launch the store, download the update, and then re-launch MSFS to complete step 1.
Although it did neither alert me to an update (there might be an “auto” setting) nor did I check my content manager, it DID boot up without the press any key screen today!