This is bias as an American who's invested in the trials system as it forces even the best to come compete with everyone and gives a nobody a shot to have a great day, and I'm not totally informed on the German system so I can't speak to what he'd have to achieve (certainly Parsons has a good shot of getting the time standards for championships), but it may be a combination of hitting the standard and competing at the German olympic trials. He may only need to get on the start line if others don't have the time.
The objection that many people on the boards about Pappas is that she's branded herself as an Olympian, when she achieved that by merely acquiring citizenship and having a time standard by default, so she didn't have to compete with others to earn the title of Olympian. Obviously this happens in many cases but she is in reality an American (she holds an American passport, grew up in the US) so it's not the same as a person in a small country that was born there or has held citizenship since birth, who often has either run the standard or is the #1 spot for their respective event. My assessment of people's frustration toward Pappas is that she brands herself as an Olympian when she really isn't *that* good and didn't get there "fairly" (I take issue with other things, primarily her use of her position as a somewhat notable athlete to break into the worlds of film & poetry when there are plenty of people who do those things full time and live below the poverty line, plus she is a pretty damn good athlete, but not filmmaker or poet, which she only is known for because she was, uhm, an Olympian) but it should be noted that she did run well in college, and did run the OLY standard. The issue here is that this criticism doesn't often extend to people such as Aisha Praught who did gain Jamaican citizenship in a similar avenue to Pappas, but that move has served her very well, her environment away from OTC with the Bosshard group has proven fruitful (Commonwealth games gold, sub 9:20 steeple, Millrose win) and she is also volunteering in Jamaica to work on promoting distance running. Pappas is a combination of a mild to majorly annoying social media presence and somewhat lackluster performances since Rio (and some on here would say even that was, but wtf are you gonna do when Ayana drops a 2:45 K in the middle of the Olympic final), but at the same time, a lot of young female runners look up to her, and that's not all bad. I'm sure she's a really nice person.