No, it has nothing to do with Expect. The problem was that the sub in which next was located did not have a loop. next doesn't work beyond a sub. That's because next is a keyword, not a function. Keywords have meaning at compile-time, but the caller of the sub is only known at run-time.

Note that perl 6 will convert next into a special die, so it might work as you expected, depending on the guts of Expect.