Yes, along with metabolic waste (measured in this case as nitrates) comes potentially other changes & issues in water parameters, such as changes in alkalinity, conductivity, TDS, pathogenic bacteria numbers, etc.
As far as TDS, if ones TDS shifts too quickly it can cause osmotic shock, which for many years hobbyists confused with pH shock, only because most hobbyists don't own a TDS meter. Osmoregulation has nothing to do with pH, and everything to do with controlling the balance of water/salt concentrations. pH has nothing to do with regards to if ones water is a hypertonic solution, hypotonic solution, or if it's isotonic. The shock part of the equation comes in when a fish has difficulty reaching equilibrium. The "high to low" shift in TDS values becomes more dangerous as the fish cells can become flooded with water faster than they can reach equilibrium, and burst .... which is where the term "shock" comes in. The biggest issue with pH is ammonia toxicity, as at higher pH values free ammonia can be much more lethal, especially when higher temps are involved.
But again, it's a sum of all evils, not simply a "nitrate" issue.
As far as TDS, if ones TDS shifts too quickly it can cause osmotic shock, which for many years hobbyists confused with pH shock, only because most hobbyists don't own a TDS meter. Osmoregulation has nothing to do with pH, and everything to do with controlling the balance of water/salt concentrations. pH has nothing to do with regards to if ones water is a hypertonic solution, hypotonic solution, or if it's isotonic. The shock part of the equation comes in when a fish has difficulty reaching equilibrium. The "high to low" shift in TDS values becomes more dangerous as the fish cells can become flooded with water faster than they can reach equilibrium, and burst .... which is where the term "shock" comes in. The biggest issue with pH is ammonia toxicity, as at higher pH values free ammonia can be much more lethal, especially when higher temps are involved.
But again, it's a sum of all evils, not simply a "nitrate" issue.