The short answer is that yes, you can override the "next" revision to occur to be manually put in by the user. It is a preference you can set at site or org level called "allow override on revise".
The issue though is that you can only override going forward in the rev scheme, not backward. Assuming a sequentially-increasing numeric rev scheme, if you had an object at rev 1 but it should be at rev 4, you can revise rev 1 and go straight to 4, skipping rev 2 and 3. You cannot do it backwards though (from 4 to 1) because eventually you will cause a conflict with the object eventually getting back to revision 4 "again", which will cause uniqueness issues.
The "real" answer is that through database manipulation there are ways to make these corrections, but it isn't easy or straight-forward. If you are interested into looking into this, please send me a direct e-mail at robert.sindelar@eccellent.com with a few more details (what WC object types, approximate counts, etc). My company has several years experience in all things Windchill and we could provide a quote for you for this project.
