Conversation so far:
Why was Pink Floyd's Syd Barrett replaced?
Working with Syd Barrett eventually proved too difficult for the rest of the Pink Floyd band members.
What happened as a result of Syd Barrett being replaced by David Gilmour?
After Syd Barrett's departure, the burden of lyrical composition and creative direction fell mostly on Roger Waters
When did Pink Floyd's Syd Barrett get replaced?
Blackhill announced Syd Barrett's departure on 6 April 1968

Question: What was significant about this?
Self-contained rewrite: What was significant about Syd Barrett leaving Pink Floyd?