Here in the UK you get 26 days leave a year roughly so it's not impossible to take a week off. I hear the US makes this much more difficult. It would have to be paid obviously.

I wonder if "audition time" could be a sort of industry standard? FAANG announced they expect/allow it and will only do business with others who do too.

Ultimately it would be better to know someone might leave soon and to get to actually know what they do while you can still ask them before they just leave and your stuck without them. But I doubt managers would welcome it.