An alternate Gundam timeline is often judged by how much it differentiates itself from the original Universal Century timeline. The fewer parallels that can be drawn, the more intrigue is generated regarding what's different. There will always be aspects present, like the Gundams, the Char clones, the space colonies, psychic powers of one sort or another, etc. However, if enough effort is put into the worldbuilding and characters, they can be much different from anything that came before. For example, a series like Gundam SEED or Gundam AGE can be criticized for how many of its story elements and plot points mirror UC plot points; they stick to what worked in the past.
Source：https://www.cbr.com/gundam-needs-new-ibo-anime/
