I don't think the author is correct, that this is a rally based on an expected rate cut.
I think this is a continuation of yesterday's rally that had 3 reasons
1. strong holiday sales
2. Abu Dabi stepping in with their petro dollars
3. stocks were getting too cheap.
The dollar is a market just like stocks, bonds and commodities.
The “short the dollar” trade has a lot of gains in it, and the Fed has put out contradictory information for people shorting the dollar in the last week.
So the Forex traders will cover their trades. When they do that, the dollar goes up - in the short term.
People need to learn to not pay too much attention to a single day, and to pay much more attention to trends. The trend on the USD has been down - hard - for a couple months.