Ive heard also this prediction that bitcoin might reach to $1M. Maybe this can be hit in the future, so for now I save bitcoin and hold for a long term investment. Yet, we cannot tell when it will be happen by that time btc is very expensive.
In the situations of btc to come more expensive maybe we can experience a very congested blokchain network in the future. If that would be possible for a price of per bitcoin into $1m, well we can expect for further massive trades and I believe that there will be more seller and buyers will come in. It will become the most in demand trading assets in the future, and only that problems may occur during btc transfers as part of the daily process of exchange digital currency to fiat exchanges.