Earlier quoted context omitted.
The quantity of money is proportional to nominal GDP/velocity (in the quantity theory of money). This doesn't tell you anything about the "price of a currency" in another currency, ie the exchange rate.
So you're claiming that if Bitcoin did $1 trillion dollars worth of transactions in a year, and people held it for a year on average, that wouldn't necessarily imply a total value for all bitcoins of $1 trillion?
The quantity theory of money is concerned with one currency at a time.
The trick in your paragraph above is that you introduced “$1 trillion dollar”. Of course, if you say that the sum of all transactions (in BTC) has a certain USD value, then you’ve brought the exchange rate in (through the back door).