The decline of international traffic to Las Vegas from places like Canada are more noticeable

The traffic to Vegas is down from all over. People simply don't have the low interest rate money to gamble anymore.

I can gamble with my money just fine.

What I don't want to gamble is with my life and freedom. Will I get detained because of spicy JD Vance memes I posted or not? Nobody knows!

Departure flights of Americans to foreign countries is up 2.9%. If that is indicative of the normal post pandemic recovery and travel growth then down 3.8% might be down roughly 6% from what it would have been. But it's possible the trend wouldn't match America's travel growth or more egress from America is being driven by related factors.

Here it says 14% drop in March.

https://www.ustravel.org/us-travel-snapshot-april-2025

I can't read the article (paywall) - does the "international arrivals" include Americans travelling overseas, or only non-Americans?

If the latter, then indeed it's not dramatic. But if the former, then the number of contingent trips to the US might have dropped a lot, and is hiding mixed in with regular unaffected traffic of USians.