Around here, a replacement would be allowed without an outside main, where a new installation would require one, if you're not "increasing the risk."
That means that, as long as you're not upsizing the service, or lengthening the cable run, an outside main doesn't have to be added if there wasn't one.
Without a doubt, you should ask whoever will be inspecting the work, and before even pricing it if you can. Otherwise, figure on adding the outside main.