Here are the limitations:

• No sequel movies, only standalone
• No Ghibli movies
  This is a 3x3 format that I think really brings out everybody’s unique taste, if you’ve seen enough anime movies to make one. If you can’t fit the limitations, feel free to break them.
  I generate my 3x3 on here: https://gqgs.github.io/3x3-generator/

To label mine: 5 Centimeters Per Second, Macross Do You Remember Love, Christmas in January
Galaxy Express 999 Movie, Weathering with You, Pompo the Cinephile
A Silent Voice, Ongaku, Tokyo Godfathers
I allowed myself to include things like the Macross DYRL and Galaxy Express movies which are remakes of existing series.