Intriguing soap characters who never showed up

[Willie Oleson]

DYNASTY had the mystery woman in season 9, and DALLAS ended with the shocking reveal that JR had a daughter.
They remained unseen because the shows were cancelled, but were there any other characters that were mentioned (or about to be introduced) in a specific context i.e. something that *could* influence the story?
Zach Powers' wife couldn't show up because she was dead (apparently…) but because of that storyline (or hinting at a storyline) she became an intriguing character.
And I thought they were going to introduce another Harper son on PAPER DOLLS but maybe that's just my imagination.

 

[Carrie Fairchild]

I'm open to being corrected here but in the Falcon Crest earthquake cliffhanger episode, Peter argues with a mystery person on the phone and threatens to "bury or destroy" them if they set foot in the US. From what I've read, this was supposed to be the precursor to his brother (reportedly played by Anthony Quinn) arriving from Greece. This never happened the following season and as far as I know, the phone call was never followed up with an alternative explanation.

 

[Marika]

On Beverly Hills, 90210, Andrea mentioned in a season 2 episode that she has a sister – a fact that was never mentioned afterwards. Her sister could have been someone like Kelly, whom Andrea initially didn't like because she was so shallow and all, and that sibling rivalry could have made Andrea a bit more interesting, if only for a short story arc. While I liked Andrea's friendship with the other main characters, her solo stories were a huge bore.

On Melrose Place, Michael Mancini originally had a brother whom we never saw. However, we were later introduced to his sister Jennifer (whom I hated). I would have loved to see Michael interact with a male family member. If Ryan McBride had been Michael's brother instead of Kyle's, his relationship with Megan could have been much more interesting because Megan was Michael's ex wife. They still could have done a Megan-Lexi-RyanMancini triangle (with Michael in the mix towards the end). Kyle and Ryan as brothers were dull as dishwater.

 

[Daniel Avery]

Knots Landing's Mack MacKenzie had a younger sister, Megan. She was mentioned several times in the year prior to his marrying Karen. When soaps do this, it's usually a precursor to this oft-mentioned character showing up to make waves in the happy couple's life (much as Abby showed up to cause strife in Sid and Karen's lives, then branched out to practically the whole town). They stopped mentioning her after Karen dealt with her pill-popping phase, so I guess they decided they had enough stuff to make Mack and Karen's lives problematic. I thought she was definitely a missed opportunity, especially in that period when Anne and Claudia were in town talking about their 'good old days' hanging out with Mack and Greg in the late 1960s. My dream come true would have been for her to show up

Spoiler

in 1992 or so
played by Constance McCashin

 

[Willie Oleson]

When soaps do this, it's usually a precursor to this oft-mentioned character showing up to make waves in the happy couple's life

Yes, it's different from casually mentioning a parent because everyone has parents. "My father used to say..." -> that's not intriguing.