Reverting back to the gold standard will never solve US' economic woes. It has to be more than that really, plus the fact that once they really proceed with such plan, gold bugs with tons of gold in their bunkers would become seemingly powerful.
Add this to the list of Trump stating preposterous things in order to 'make America great again' but continues to drag the US down with his administration and careless remarks on literally about anything. If you give the power to a man-child spending lots of time on Twitter rather than doing whatever job a president has to do, you will have these ill results the US is experiencing right now. Now you have this statement, without even thinking of the possible outcomes of such a move. Classic Trump for publicity since the election is also nearing once more.
Now going back to the gold standard, what I think would strengthen the US dollar is to not make it backed by gold but rather improve economic policies and trade relations, not with scaring off other countries by being the big man with the big guns!
Trump has talked up the gold standard in the past to please conservatives but the notion is ridiculous at this point in time. It would only be done after a full US government default and currency reboot and even then, an outright gold standard is unlikely.
That's how I actually see it as well. Him saying things about reverting back to US' roots is just to please people that he needs in order to help him vie for a re-election. No such thing as 'reverting to gold standard' will ever happen again, as most countries still find confidence in the US dollar amid the crises that are happening around--plus the fact that they have loads of the said currency in their stash, too.