It's apparently a response due to a noticeable increase in apprehensions over the last 6 years.
But i guess ticking “we did something” checkboxes keeps the paycheck deposits flowing.
Not anymore, not right away anyway:
> The new terms allow each country to expel asylum seekers who apply for protection within 14 days of crossing the U.S.-Canada border between ports of entry.
https://www.americanimmigrationcouncil.org/blog/us-canada-ex...