Absolutely no surprise at all.
The US has a grand total of 20 trade deals. There is the Canada-US-Mexico agreement (NAFTA), a bunch of trade agreements with small developing nations in S. America (intended as part of growth / stability strategy) and then some of the usual suspects who have agreements with many, many countries such as Israel and Singapore.
For comparison, the EU have around double the number of trade deals, and usually with bigger and more complex economies (Japan, Canada etc).
The US has no FTA with any large trading entities such as Japan, or EU, or Mercosur.
There is a reason for this. The US is a huge economy and any FTA will be heavily biased for the US to be interested. In most cases, this inbalance makes a FTA with the US very difficult for the other country.
A Bigly FTA was unlikely even under Trump. And such a FTA would take many years to negotiate rather than a short term "Brexit benefit".
The EU and US got closer than most with TTIP, probably because the gains on either side were somewhat more even. But it took years just to get to a situation where it was ditched.
The Brexiteers who thought this trade deal was a realistic option in the short or medium term were either lying to themselves or to us.