So you never encountered a situation when dialogues change based on story progression?
gues you are a bit to early in the game than.
Obviously dialogue can change, but why would I expect it to have IN THIS CASE? If Rick had previously said anything useful to establish him as a source of meaningful information, it might be different, but he's basically just chatted shit about everyone. If I had any reason to expect he'd be the source of information here, it'd be different, but, as I've said, there's no reason to think that.
People talk and kids are curious, obviously the elders must have told the kids a reason why Tia is different and why they should keep their distance or at least be careful around her.
People don't talk about serious matters much around children that are only a few years old, kids that age barely give a shit about anything, and people have almost no memories of those ages in the first place. No, that isn't obvious. You seem to have just made it up. I certainly haven't seen any explanation from anyone, and the only dialogue so far has been Rick saying he doesn't like her because she's big and strong.
Failing to follow the devs logic (which seems to be a personal issue since most guys got it on the first try) is not meta game or bad design.
I see this is an personal issue to you but really makeing any more obvious hints would make this a VN with combat elements... you are supposed to walk around and explore the changeing world.
Any time you make a decision in a game based on knowledge from outside the game is metagame and bad design for rpgs. You know, like noticing that a character has dialogue options, and so assuming they must be the person to talk to about something even though you have no in-narrative reason to think they'd be the source of that info. That isn't to say you won't think that, but there should be an in-narrative reason for you to talk to that person also.
Metagame aspects can be good in non-narrative contexts, like color coding in games to communicate where to go, or what you can interact with can be very useful.
If you like bad game design and nonsensical puzzles to progress them, that's a personal issue of yours.