We can certainly look at introducing Long data type support for the RevisionNumber.

As for the overflow scenario, we can certainly consider logging some warning or worse rolling back the transaction if this situation is detected. The former does allow the creation of data that does impair the fetching of data properly for revisions. The latter impacts the business function. Personally, I'm inclined to say we can log a warning of sorts, but this is really the responsibility of a DBA to keep an eye on tables where rows are increasing or where sequence values are nearing their cap.