From the article:

Can Trump really order the Treasury to stop minting pennies without Congress’ approval?

Yes, according to legal scholar Laurence H. Tribe, the Carl M. Loeb University Professor of Constitutional Law Emeritus at Harvard University.

U.S. code gives the Treasury Secretary the authority to mint and issue coins “in amounts the secretary decides are necessary to meet the needs of the United States.”

Like many things people say won't be done due to '3 branches of government', yes.

Besides, don't we have the hindsight of precedence?

Canada started phasing out its penny a dozen years ago and urged store owners to round prices to the nearest nickel for cash transactions. Electronic purchases were still billed to the nearest cent. The move came after New Zealand, Australia, the Netherlands, and others dropped their lowest-denomination coins.

After Canada stopped minting new pennies, it began recycling them for their “valuable” copper and zinc, according to a 2022 report from the Canadian Mint.

He's doing it solely because he knows it somewhat popular, thus he won't get as much pushback when he commits this incredibly illegal overreach.

I suggest reading the article.