So, the way I like to look at it, is unless you are writing a very specific genre, most people are reading to read exceptional stories, not ordinary ones.
So sure, maybe it doesn't happen often that these two people would meet like this (think about many of the meet-cutes in romcoms, like Notting Hill. HUGELY unlikely), but people still want to read about what would happen in a world where they did. And they want us to make them believe it could.
You have to make it believable enough to carry the event - so each character here has to have a believable reason/motivation to be there, and to notice/engage with the other person.
I cannot get the summary tag to work lol so I'll steer clear of spoilers in case anyone is going to read it
In Parasocial, the "inciting incident" is a massively unlikely meeting followed by an even more unlikely reaction to that.
It's not at all a likely event, but I hope that the way the scene is constructed that both characters seem like they have valid reasons to be where they are, and for what happens next.