just tested: Win11, 64 bit client, I do have 'keep launcher open'.
press the dragon button in the lower left corner, select 'Main menu' Hello desktop.
My wife, same setup, does NOT have keep launcher open active, does not crash.
Edit: further tested by turning 'keep launcher open' off, did NOT crash to desktop when opening main menu.
Edit2: logged in a couple alt accounts to grab the dragon archtype, on a FTP account, same computer that did not crash with the launcher set to close, crashed to desktop when opening main menu via the button and selecting main menu.