It doesn't say donors send people in their place. It says donors can designate an attendee. It looks almost certain that the donor who pays 100k also gets to go to the conference. If the donor didn't get to go, then the part in the article talking about the donor not having as good of a time if the attendee weren't booted makes little sense.

The article also makes it clear that unimportant attendees can be booted by donors... and apparently barred from coming back in future years as well.