(into  ...) is not always equivalent to (vec ...), for example when the argument must be used within a reducer (a common case with core.reducers functions). In these cases, "into" works since it uses reduce internally, whereas "vec" doesn't.
Maybe this rule should be deactivated by default.
Adding comments to suggestions is being tracked in #107. This would let you explain the difference between into  and vec when suggesting the change so people can understand when it's not appropriate to use vec.