I've just discovered that the simplified form of the character 没 is different from the traditional form (沒). With them both being nearly identical with exception of a single stroke, why was there a need to alter it at all? Does anyone here know the origin of the change?
"Simplification" is a process. If it's not reduced in stroke count, it's not actually "Simplified" - the mix-up in language is due to PRC's standard of Chinese being popularly known as "Simplified Chinese", even though PRC Chinese may have the same number of or even more strokes.
「没」 came from a popular variant of 「沒」, because the right hand side of 「没」, 「殳」, occurs more frequently among characters, while the right hand side of 「沒」, 「𠬛」, occurs in...「沒」.
It is important to look at a character's earliest traceable meaning before further analysing its components.
Some of the earliest traceable meanings of 「沒」 is to be underwater / be submerged (cf. 「沉沒」). This is the reason for its 「氵・水」.
「殳」, if it's a semantic component, is usually used as an active verb marker, cf. 「發」 (to shoot arrows > emit), 「擊」 (to attack), 「殺」 (to kill), etc. 「殳」 is therefore not a semantic match for the meaning submerge (and is not a phonetic match for the sound of the word either).
So, what exactly is 「沒」?
「沒」 was originally a compound of a hand 「又」 under deep waters (represented by a whirlpool 「洄」). 「回」 was later gradually corrupted into the shape of 「勹」 or 「刀」.
Note: as a consequence of this development, we can be certain that 「𠬛」 was not really a character before, but was made up to decompose 「沒」 into 「氵・水」 and something else.
Can you even call this simplified?
No, it's called 新字形 ('New character forms'). Check out wiki: https://en.wikipedia.org/wiki/Xin_Zixing https://zh.wikipedia.org/zh-hans/%E6%96%B0%E5%AD%97%E5%BD%A2