In the flashforward to their 40th birthday in August, Kevin said his fiance had morning sickness. People thought that meant the Kevin/Madison hookup couldn't have led to the pregnancy, because she'd be pretty far along for morning sickness by then. Perhaps that was a hint toward hyperemesis gravidarum, which can persist throughout a pregnancy and is more common with multiples.
I was looking back through the forum yesterday and read the episode thread for "The 20s", which showed Randall as an anxious dad-to-be eager to be the perfect parent. It also featured a storyline where Kevin tried horning in on his roommate's audition opportunity, and there were comments... Also stumbled across the site's "It's Time to Boot Kevin Off This Is Us" article. LOL, the worm has turned, but we have two more seasons to go and Sterling is a brilliant actor. Remember when Kate said that only she could carry on a piece of Jack Pearson? That was a "yikes" moment that didn't go over well.
Anyway, it's really interesting how many of Jack and Randall's actions were shaded as heroic/noble early on but as the series continued, their behavior got cast in a harsher light.