Yes. Waterproofing, a new or replaced sump, slab cuts for plumbing, a basement finish, or crawl-space work can change how soil gas gets in. The Ohio Department of Health recommends retesting after significant renovation, whether or not a system is installed.
More detail
Wait until the work is done and the house is back to normal operation, then test under closed-house conditions like any other test. If a mitigation system is already in place, leave it running; Ohio requires the tester to record on the report whether a system was present and operating. Three Central Ohio projects deserve special attention: interior drain tile and a new sump added to a wet Gahanna or Worthington basement, which changes what the sump cover has to do; a bathroom roughed into an older basement slab; and an addition built over a crawl on a postwar ranch. Note Ohio's rule on changes to the system itself: altering a mitigation system means bringing it up to the current Ohio standard, while simply swapping a worn fan does not. See finishing a basement the radon-smart way.