I have to agree that I'd prefer the final boss fight not to be skippable "by accident", and I'm kinda glad the bug existed when I first beat the game. From what I see in videos on youtube or twitch, too, the reaction to Scyrioelaphas fighting the Guardian in your stead is less of an "awesome, I found a way to get around fighting the final boss" and more of a confused and slightly disappointed "wait, this game doesn't even have a final boss?". I think the reason for this is that you make the decision to free Scyrioelaphas many hours before the game ends, it's a "good guy" decision so most players will choose it, and it's not immediately connected to the idea of getting around the final boss battle. Player aren't aware that not having a final boss battle is a direct result of their choice, and it feels anticlimactic. In my opinion, a better way to have freeing Scyrioelaphas matter would be to have the Guardian start the final battle wounded in that scenario.