Ok, so there's a lot of extreme ends going on all throughout this thread, so I'll bring the middle ground:

The way I do it is if they didn't watch the guide, I give them a brief 60 rendition of the key mechanics(like the marks for swift liberation in ravana for example[not that people listen to that anyway because tunnel vision])
I apply this same rule to people who also haven't done the fight in a long while since they key mechanics are the biggest memory cue in most cases.

Then for those who do watch the guide and struggle, I'm more than happy to give them tips and advice or explain more in-depth.

I do have one exception to not watching a guide: If I see you're actively trying to learn the fight(like asking if you did a mechanic a wrong way), You get a pass since you're putting in effort and imo if you put in the due effort, you always get an A.