Here is a quick list of of some of the traditions that were ... altered?

1. Joe Biden Flies on Charter Jet Not Government Plane for Inauguration Trip to Washington, DC "Typically, a president-elect travels to Washington, DC, for the inauguration aboard a plane in the fleet used for Air Force One." Source: https://www.breitbart.com/politics/2021/01/19/joe-biden-flies-on-charter-jet-not-government-plane-for-inauguration-trip-to-washington-dc/
2. Melania Trump to Jill Biden: No tea-and-tour at White House, breaking longstanding tradition "In modern history, there has always been an invitation, this goes back to at least Bess Truman and Mamie Eisenhower (in 1952)," Source: https://www.usatoday.com/story/entertainment/celebrities/2021/01/15/melania-trump-jill-biden-white-house-tea-and-tour/6602559002/
3. Melania Trump to Jill Biden: No tea-and-tour at White House, breaking longstanding tradition "Traditionally the 'football' is handed from one military aide to a new designated aide at midday" Source: https://www.telegraph.co.uk/news/2021/01/19/will-trump-hand-nuclear-football-biden-skips-inauguration/
4. No, There Will Be No Inaugural Ball This Year "We'll just have to wait for our Dr. Jill Biden-VP Kamala Harris gown moment." Source: https://www.harpersbazaar.com/culture/politics/a35270752/joe-biden-no-inauguration-ball-2021/ Source: https://www.youtube.com/watch?v=gKIwOgNEqBM
5. Why were the Bidens locked out of the White House? (hahahahaha) "Washington: It was the culminating moment of a transfer of power: President Joe Biden and the first lady, Jill Biden, walked up the driveway to their new home late Wednesday, ascended the steps to the North Portico, waved to the crowd as a military band played "Hail to the Chief," turned to head inside - and came face to face with a closed door." Source: https://www.msn.com/en-ae/news/other/why-were-the-bidens-locked-out-of-the-white-house/ar-BB1cZaph
6. 21 canon solute TRUMP 4x CANONS: On Inauguration Day 2017, the Presidential Salute Battery (The Old Guard) conducts a 21 Gun Salute in honor of newly sworn-in President Trump. Source: https://www.youtube.com/watch?v=sN1zIJc8PUU BIDEN 3x CANONS: (CBS NEWS) After receiving gifts from congressional leaders, Mr. Biden and Harris participated in the traditional Pass in Review Wednesday (1/, during which they reviewed military troops at the East Front of the Capitol. Source: https://www.youtube.com/watch?v=UIprRLYcteA&feature=emb_title

7 [Recently added]) Not Just for Ordering Diet Coke: The Red Button on the President's Desk "It's not clear why Biden has had the button removed. And the fact that a Presidential drink-ordering button has made national news perhaps signifies less panicky political news coverage for the time being." Source: https://www.core77.com/posts/104353/Not-Just-for-Ordering-Diet-Coke-The-Red-Button-on-the-Presidents-Desk

Please add to list?