Conversation so far:
who left vampire weekend?
Rostam Batmanglij announced his departure from the band on Twitter.
why?
collaborate.
What did he want?
Batmanglij contributing to the record.
The album's working title was revealed to be Mitsubishi Macchiato.

Question: What did he move on to?
Self-contained rewrite: What did Rostam Batmanglij move on to?