>>JBiser+(OP)
Announcing guests late for a convention (when the arrangements might not have been finalized until that point) is "a dick move", because some attendees might not like the idea of the guest being there (despite no compulsion to interact with said guest) and find it too late to cancel (on things they voluntarily committed to based on the existing expected content, fully accepting the risk of future change)?
No, I think the dick move (in the https://www.youtube.com/watch?v=0la5DBtOVNI sense) is raising hue and cry because the opportunity to see another influential person at a convention somehow ruins the rest of the convention for you.
And are we seriously arguing that the creator of the thing should be barred from a convention about the thing?