That's unlikely to be true. They might buy less, but the numbers won't fall to zero.
It also overlooks the detail that the component parts of items "made in the usa" also come from other places. Clothing made in the US, doesn't necessarily use fabric made in the US.
In the short to medium term, the increased cash-flow requirements (tarrifs are paid before sales) will favor large importers with access to abundant cash over smaller importers.
Yes, the purchasing power of US consumers will go down as retail prices of goods go up. Yes global producers will seek out alternate markets.
The current uncertainty causes US purchasing to prefer not to commit to long-term orders. Global suppliers will prefer orders from stable customers, even at somewhat lower prices. Once those long-term contracts are in place, it may be hard to reenter the global marketplace, especially on the currently favorable terms.
In other words tarifs are doing long-term reputational damage that will not be easily undone in a few years time.
On the up side the world is about to observe, for the first time in a couple generations, the effects of an isolationist policy. It is a valuable lesson that needs to be reinforced from time to time.
The US has made friends with a lot of countries based on the goodwill generated by strong trade ties. That goodwill is being eroded in the short term, and will linger as a reputation for "unreliability". 80 years of work is being undone in months.
And unfortunately it won't be as simple as "in 4 years we can go back to normal ". It's obvious that congress supports this, and the American people voted for it, so it's not just one man's policy.
Is the rest of the world suddenly going to start buying something they haven’t in the past? Why?
And the US consumer market is 2x the size of the next biggest (EU).
How exactly is the the rest of the world going to replace the demand of something several times its size?
https://www.chiangraitimes.com/china/china-export-dumping/
Obviously the profit margin will be less than selling to the US, but it does mean that the 3% of GDP mentioned above is not going away entirely, just shrinking to (say) 2 or 2.5%.
The article also mentions transshipment, where Chinese goods get routed to the US via a third country. Although Trump's strategy of "tariff everybody for all the things" is putting a damper on this too.
OT: Solar is awesome! 18 panels are generating 2/3 of our load, despite it being late winter. And a 16kWh battery means the grid power we import is all off-peak. In summer we're going to be exporting enough that we may even cover our winter grid import. Plus it gives us the best UPS system we've ever had, including zero-second cut-over (c.f. Tesla's half-second glitch).
So the world needs to absorb almost half a trillion of new supply.