The top players really have no trouble with whatever SE puts out. I think its only 5-10% of the playerbase that clears final coil of Bahamut every week. But those players will clear the raid regardless of the mechanics because they are skilled.

Its the middle and casual players the ones who don't clear final coil that have a problem with clearing content. Randomness is an difficulty increase in most cases will only have a effect for mid or casual players. Hardcore players will still clear it.