Alternate Gilligan's Island Part II: The "Silly Alien" Episode that Never Was

In my post yesterday I referenced a YouTube video describing the possible plans for a fourth season of the Gilligan's Island TV series before it was canceled. The list of ideas is ten episodes which is roughly a third of a season and I am skeptical that the list would have been in the order the episodes would have been broadcasted. I believe Ginger (Tina Louise) would have been rescued from the island during the first episode of the fourth season even though that story idea is listed second.

For this post though let's focus on the ninth story idea in the list:

1. "My Favorite Alien": A silly alien lands on the island.

For a caveat I am assuming for this post that the "silly alien" isn't Bumper from Gilligan's Planet. Yeah, that cartoon series exists in our timeline but somehow a fourth season of Gilligan's Island doesn't.

If a fourth season had happened it would have been originally broadcasted roughly between September 1967 and April 1068 based on the airing dates of seasons two and three. Sometime during that alternate history's fourth season the "My Favorite Alien" episode could have been broadcasted. I imagine that Jerry Van Dyk would have portrayed the "silly alien". Jerry Van Dyke had almost been cast as Gilligan in the series but opted for being in My Mother the Car instead. My Mother the Car was canceled before a fourth season of Gilligan's Island would have been in production so that guest star role seems like it could have happened.

Here is my question: In an alternate timeline in which a fourth season of Gilligan's Island occurs based on the list of ideas cited in yesterday's post; does the Mork & Mindy series also exist? I believe in that alternate timeline there is a better than 50/50 chance it doesn't.

In our timeline Mork of Mork & Mindy was introduced in a Happy Days episode. Morky & Mindy was a spin-off from that episode titled "My Favorite Orkan".

Imagine if that event from late '70s TV was mirrored back in a fourth season of Gilligan's Island. A silly alien shows up on the island, hilarity ensues, and that silly alien was popular enough to have gotten a spin-off series on late '60s CBS. That alternate series silly alien spin-off wouldn't have had Robin Williams or Pam Dawber. It probably wouldn't have been set in Boulder, Colorado. Being a late '60s series it probably would have been a silly alien being taken in by a family so it would have been a larger humanoid form of ALF.

Even with the popularity of Star Wars at the time why in this alternate timeline of fourth season Gilligan's Island existing would the ABC network have done a silly alien series spin-off when CBS had already done it a decade earlier?

In my post yesterday I expressed the opinion that losing the Ginger character for two new female characters in a season four of Gilligan's Island would have been a trade up for the show. Maybe in the big picture I am mistaken. By losing Ginger maybe we would have lost something else. Instead of Robin Williams being Mork from Ork he would have just been some guy looking for directions to Highway 41.