Maybe it means that if you are _always_ exposed to high CO2 your body adjusts, but if you are sporadically exposed it does not? Kind of like living in the mountains vs going there occasionally
Fortunately, we're really good at compensating for blood acidification. It's offset with higher bicarbonate levels and more excretion, which means the reaction uses carbonic acid and hydrogen to offset carbonic acid - pretty low-consequence to produce. Having more bicarbonate raises calcium and potassium levels slightly, but even when it's way outside of any normal exposure it doesn't seem to cause further effects.
Only true if adjustment isn’t giving up higher functioning of the body for a less efficient metabolism.