It was certainly possible to fry the electronics in an SLR with electronic sync not designed for use with studio strobes before digital, and even mechanical sync contacts could be degraded over time by arcing from high voltage shutters. I don't worry too much about the mechanical sync with my Norman portable and studio strobes, figuring that it's one of the things that can be adjusted or repaired with a regular CLA, but with electronic cameras I use a Wein Safe-Sync to reduce the trigger voltage to safe levels. The risk is probably low, but it's easy enough to avoid.