Acts 16:6-7 has a curious narrative, in which it is explained that the Spirit forbade Paul and Silas to preach in Asia, even though they very much wanted to, and that they were further forbade to preach in neighbouring Mysia and Bithynia. This narrative is really strange, when you start to think about it. Why does Luke feel the need to go out of his way to explain that Paul intended to travel to these regions, but didn't? He doesn't even mention that Paul preached in Arabia (as we know he did on the grounds of his own writings), so why does Luke go out of his way to mention that Paul didn't preach in Asia, Mysia, or Bithynia? I would suggest that Luke's narrative only makes sense if we understand that early readers would have expected Paul to evangelize in those regions. The answer is, Why would they expect that Paul did such?
I begin with my conviction that the earliest Christians believed that in their operations certain HB/OT prophecies were being fulfilled, especially those of the last chapters of Isaiah. I then note that in Isaiah 66:19 YHWH states that he will send "survivors to the nations, to Tarshish, Put, and Lud—which draw the bow—to Tubal and Javan, to the coastlands far away that have not heard of my fame or seen my glory; and they shall declare my glory among the nations." Now, this is where it gets interesting. There is good reason to think that by the first century "Tarshish" was frequently identified in Jewish exegesis with Tarsus, i.e. Paul's hometown, and that this was expanded into Cilicia and perhaps southeastern Anatolia in general. "Put" almost certainly was taken to refer to Cyrene. Josephus identifies "Lud" as the ancestor of the Lydians, and ancient Lydia of course laid largely within what was by the first-century Roman Asia. Rabbinic literature identifies Tubal with Bithynia. Javan was generally identified with the Greeks (indeed, the LXX renders it as "Greece" Ἑλλάδα), and in rabbinic material more specifically with Macedonia. The LXX also includes a reference to Μοσοχ between Lud and Tubal, which seems to correspond to Meshech, which the rabbis apparently identified with Mysia. (Riesner attempts to suggest that Second Temple Jewish exegesis located Put in Anatolia, in or around Cilicia, but I find his arguments unpersuasive).
Cilicia; Cyrene; Asia (Lydia); Mysia; Bithynia; Greece. This is almost exactly the order in which Luke attempts to narrate Paul's missionary journeys in the Diaspora. There is work in Cilicia and thereabouts, interrupted by intervals back "home" at Antioch and Jerusalem and Cyprus; then the effort to enter Asia; then the effort to enter Mysia; then the effort to enter Bithynia. Then, Paul heads off to Greece. Only Cyrene stands out, but three notes are in order. One, Luke goes out of his way to highlight the role of Cyreneans in the early spread of the gospel to the Gentiles; two, he frequently links Cyrenean Christians with Cypriot Christians; three, there is evidence that the Cyrenean and Cypriot Jewish communities had a particularly close relationship. I would suggest that Luke was aware that Paul never traveled to Cyrene, and thus did as much as he could to bring Cyrene into a geographically-structured narrative as close to the place where it should have appeared. This also accounts, I think, for why he neither mentions Paul's time spent preaching in Arabia while also going out of his way to explain why Paul never entered Asia, Mysia, or Bithynia: the former did not fit into his geographical scheme, while the latter was mandated by it.
But here we come up against a question: why didn't Luke just make up Pauline journeys to Cyrene, Asia, Mysia, or Bithynia? And the answer is deceptively simple: Luke didn't just make things up. His aim was precisely to show how prophecy was being concretely fulfilled in the activities of the early Christians (cf. the language of Luke 1:1). That aim was incompatible with just making things up. But it was not incompatible with an attempt to "bring out" what Luke considered to be the divine plan evident in the pattern of those activities. This created situations wherein the messiness of history did not conform to Luke's relatively tidy prophetic schema, and Luke had to account for that. His account not surprisingly conformed to the theological outlook that structures his work: the Spirit decided that Paul was not to operate in these areas.
If the above is a correct interpretation then the following seems also to be the case: Luke could expect his readers to be aware of the geography of prophecy found in Isaiah 66:19. He could expect them to expect that Paul would enter into Asia, Mysia, and Bithynia. Otherwise it is hard to account for why he would feel a need to give an explanation. He could have just passed over it in silence. It is precisely because these particular prophecies of Isaiah 66 were not fulfilled by Paul (again, cf. Luke 1:1) that he must mention them.