I was hoping this will be something new in FS2024 but as I poke around in the new sim, it does not appear this aspect of it has changed since the last one.
As the MSFS is tied to Xbox account / MSA, the Gamertag as it exists on the account on Xbox.com is what is shown in the sim. This may be fine for most games, as this is an aviation world where planes are identified by flights and regs, being able to be in the world as “N24936” (don’t bother looking up, it’s a Flight School aerobat that has been scrapped a while ago) is a lot more “immersive” than say “DragonSlayer12345”.
I can understand that for licensing and accounting purposes, we will need the account to be tied to an Xbox account but it would be good to be able to live in an “aviation world” within the sim.