The Libretto for tomorrow’s papal inauguration shows that Pope Leo XIV will stay with the present practice in the constitutions and not revive the practice of wearing the Papal Tiara. The last pope to wear the tiara was Paul VI, with an unusually fashioned bullet-shaped design, which was later donated.

Like Pope Benedict XVI and Pope Francis, Pope Leo XIV will not use the traditional headgear in his coat of arms, opting for the three-tiered mitre instead. Pope John Paul II retained the tiara in his coat of arms but permitted it to be seen without the tiara in the later days of his pontificate.
Pope John Paul II explained this reasoning by saying that the tiara would be seen as an image of temporal power:
“This is not the time to return to a ceremony and an object considered, wrongly, to be a symbol of the temporal power of the Popes.” (October 22nd, 1978)

The imposition of the pallium and the bestowal of the fisherman’s ring will still be present for the inauguration. It is still possible that Pope Leo XIV may adopt the use of the traditional tiara later in his pontificate as some speculated Pope Benedict XVI might do but it would likely take a change of the present constitutions in order to change the present state of Papal ‘inaugurations’ back to the more traditional practice of coronations.
For more history of the papacy: