The accepted answer to Are there any guidelines in place governing the extent to which magic items can resize to different-sized users? only shows that "worn" magic items are supposed to resize to fit the wearer - not weapons.
I am interested whether the properties of the following artifact demonstrate that magic weapons also resize to fit the bearer.
The Sword of Zariel is found by players towards the end of Descent Into Avernus. Its previous wielder was the angel Zariel - who is (at the time the players find the sword) a Large fiend, and used to be a Large celestial (a Solar). Since this is an artifact weapon that literally bears her name and was thus presumably made bespoke for her, it seems safe to assume the weapon is sized well for her former angelic self - and thus is sized well for a Large creature.
Players can (if worthy) attune to the sword. Its stats are presented in the book; it is a longsword, and neither in the stats nor elsewhere in the book is it suggested a Medium/Small PC would have difficulty wielding this sword due to their size.
Given these two facts, must it be true that this artifact weapon can resize to best fit its wearer, whether Small/Medium or Large? And if so, does that mean that all magic weapons can do this?