[TokuKnight89]

There seems to be some confusion regarding Master Vile's Orb of Doom and its chronological properties. It's stated that it reverses time, but I think that it's more an alternate timeline than
a depiction of what really happened in the past.

Two key details are the idea that Aisha's family history would change given that she stays behind while Tanya returns with the Zeo Subcrystal and another is when Cestro returns to the Earth during the Hydro Contaminator incident in Zeo and Bulk and Skull don't seem to recognize him despite their younger selves admiring the Aquitar Rangers during the Alien Rangers Arc.

For frame of reference, MMPR Season 3 and the Alien Rangers Arc was around the '95 timeframe, which pairs well with X-Men's "Age of Apocalypse" storyline which was understood to be an alternate timeline at the time.

I think the Orb of Doom turned the clock back and led to an alternate timeline, but ONLY ON EARTH! When Zedd, Rita, Hydro Hog, and the Alien Rangers head to Earth during that point, they ultimately enter that "temporal bubble" and become part of the Earth's past in this alternate timeline.

The main MMPR team remains friends cause where someone is at the exact moment of the temporal inversion caused by the Orb of Doom will determine the personal and familial history in the alternate timeline. To put it another way, Kat was probably not in Angel Grove during her childhood in the main timeline. However, since she was in Angel Grove when time was "reversed", her personal and familial history has "changed" and therefore she is in Angel Grove as a child in the alternate timeline. This is the best explanation I can think of regarding Aisha cause some have theorized that because she stayed behind before time was restored, the timeline was altered and she never became a Yellow Ranger. Personally, I don't believe that the timeline was so distorted that Aisha's Ranger history was erased. I believe that when time was "restored" by the Zeo Crystal, Aisha's personal and familial history was also affected. Where you are during a temporal inversion will affect you and your family and where you are during a temporal restoration will also affect you and your family, thus the main timeline after the restoration by the Zeo Crystal now has Aisha leaving the Rangers to help out overseas without totally erasing her Ranger history.

That's my take on the Alien Ranger Arc.