Have seen legit success with AP J4 in ARAM with some spicy flag ludens spam, although that's probably more the exception than the rule.
Don't think picks/builds of any sort are inherently trolling, although sometimes a bad idea, but bad ideas are a skill reflection and you can't report someone for being bad at the game. If some poor soul thinks AP graves is the future, they're free to do so, but their 'punishment' will be sinking to the depths of bronze mmr rather than being banned or whatever.
Those who are actually picking poorly with the intent to troll, tend to clearly troll in other ways that are more clear cut (inting/griefing) and it's that sort of thing that gets reports that end up being actioned by riot.