I think you may be thinking of changing the show file while the show is running, which does cause the show to restart.
Changing the sequence while the show is running does not cause the show to restart. It also may or may not cause the new version of the sequence to be used in the current show. Depends on whether or not the Show Player had already loaded the sequence by the time the changes to the sequence were saved.
Also, even if the Show Player had already loaded the sequence, it's possible that it will "unload" it after it's done playing (due to memory usage considerations). If that happens, and if the sequence is eventually played again during the same run of the show, the Show Player will reload it at that time. So for sequences that play more than once per show, it's even possible that the Show Player will use the unchanged version of the sequence for a while, but then switch to using the new version of the sequence. This switch will never happen during the sequence - once the sequence is started, it will keep playing whatever version it started playing, until the sequence ends. But once the sequence ends, the next time it restarts, it may or may not start the new version.