That lever was originally just put there as set dressing; in the original it was inaccessible, but I always thought the fourth secret should be hidden up there; it was the difficulty of having the lever there too that made me not add the fourth secret in the original release.
For this, I decided I wanted to put it in. I considered having the lever broken and do nothing, but I figured with a simple flag I could make it safe to use. Typical a player immediately broke it...