Q: What happens if two players simultaneously meet the current win conditions in Fluxx? Is it a tie?

A: There generally aren’t really ever ties in Fluxx, because of this simple, elegant rule:

If two players simultaneously meet any win conditions, the game continues until there is a clear winner.

Usually the Goal simply changes, and the multiple people in question are simply no longer meeting win conditions at all, though there are other ways the situation can change.