I am rather conflicted. On the one hand, it is a spectacle that is woefully uncommon in the West, which is a shame. Pomp and circumstance is always lovely. Further, the men in the crown's congress's clothes ought to be given a chance to display themselves, and have a special day out. It would boost morale, and, above all, be a fun and impressive occasion.
On the other hand, I believe that a president ought to have something in particular to show for himself before he calls what is effectively a Triumph. For it simply does not seem, on the whole, to be an occasion to praise and display the United States military. No, it more seems as an attempt for President Trump to bathe himself in glory. And, whatever one might think of his presidency thus far, there is no achivement in particular that truly accompanies well to the sound of drums, fifes, boots and tank treads. No music can match it, and him simply being on the presidential seat does not warrant it.
However, if he ties it to an occasion, say a Veteran's Day, or in the memory of some great victory or campaign, it could work. If, and that is a significant if, he has the sense to stand back a bit. President Putin has the Victory Day, and that is wise. He can bathe in the prestige that it brings, without seeming to claim it, or having to present good grounds for a personal Triumph. It does not belong to him, that day, but all of Russia, and the soldiers of the Great Patriotic War. He is merely the masters of ceremonies, and reaps the rewards thus.
President Trump would be wise to arrange something similar, if he does not want the parade to seem like an act of vanity.
EDIT: It appears that the current fancy was inspired by the Bastille Day parade of Paris. Well, I can think of worse ideas, but nonetheless. It must be managed quite carefully, if it is not to become an unworthy matter of compairing big boy's toys.