Yes, I don't understand the parlimentary system or the Canadian government well enough to get how it works either. Isn't it possible that like Theresa May Trudeau might not last a full term? So his promise might be pretty hollow.
In any case Trudeau is a great friend so I'm sure as long as he is in power they'll get special treatment. She snubbed Trump and he has a thin skin so he won't do anything for them. Probably why they won't come until he's out of office. But the next person might be the same way.
Yes, it's very possible his tenure as prime minister will not last very long.
(The situation in the UK was different, Teresa May resigned as leader of her party, Boris Johnson is from the same party and was chosen as the party's new leader and therefore, the new prime minister. In a parliamentary system, the leader of the party in power is the prime minister). For Trudeau, the issue is not within his own party but will they keep support of parliament in general? A no confidence motion from the opposition parties that passes would trigger a new election and probably another party in power. There aren't fixed terms in the parliamentary system like the American system.
As Trudeau is the leader of a party in a minority government because they won with a narrow margin of victory, it is unlikely they will last more than 2 years before another election at most (history has shown this). Minority governments can fall at any time with the passage of a no confidence motion.
At any time, an opposition party can bring forward a no confidence motion, having the other opposition parties support it so it passes. If it passes, the Prime Minister asks the governor general to formally call a new election within 50 days. The ruling party then is almost always defeated in the following election. No confidence motions can be called at any time although they are used strategically, they are called when the opposition parties agree to support it and think they will win the next election (or get concessions in a future government from the party they support). As well, they will propose no confidence motion only when they feel most voters are in agreement with them and they are likely to win the next election.
https://en.wikipedia.org/wiki/Motion_of_no_confidence#Canada
Our last federal election was October 2019. His party only won 36 seats more than the next party, they won 157 seats out of a possible 338.
The only thing that Trudeau and the Liberals have going for them is that the current leader of the Conservative party (the largest opposition party) is not popular within his own party.
Historically minority governments in Canada only last 2 years at most, some have been less. In contrast to majority governments are much longer lived. They can last more than 4 years, sometimes to close to 5 years. In a majority government, the ruling party decides the time to calling a new election is usually based on favourable polls.) No confidence motions are not an issue when a party wins a majority government because there is no point of proposing them then.