I believe you are using deflation/inflation in the opposite way usually meant on these forums. Mostly we speak in terms of monetary deflation/inflation, where deflation = higher BTC prices.

The block reward halves every four years, so hopefully it will become insignificant by the time growth "loses steam". Assuming Bitcoin is not replaced by something else, prices should continue to rise forever, since people will lose bitcoins even when the price would normally be totally stable. But that's not really the point: the point is that value won't decrease unpredictably.