Those all fall under the “jump straight in” category. If you can read the situation well, e.g. who is up for being approached, and who isn’t, then they work well for making new friends. Unfortunately, if you don’t yet have those basic social reading skills, it’s a minefield.
Incidentally, I’m fully past that set of issues. I used the fact that no one has any idea what’s going on at the start of university to practice and build skills.
I also help out with a nerd related social group. Neurodiversity is the heavy majority there. We often have people come along that are accidental shut-ins and want to meet people. I now make a point when showing them around to both make it clear that everyone there at that time is there to socialise and show stuff off. I also introduce them to a few people to break the ice. Watching people come out of their shell and realise they will be celebrated for their weirdness, not punished for it feels very good to me.
I’ve been on the receiving end of social punishment more than enough to call anyone risking it brave.
My experience with young children is that they can be incredibly welcoming, and accepting. Only a few tend to be like you claim. They generally want to be friendly and be liked.
Unfortunately, they are also still developing and learning social skills. They often can’t tell different and guarded from hostile. They will often reflect back how they feel they are treated. This becomes a vicious cycle.
It’s about 8-9 that things like clicks can form. Social skills explode in complexity. This is where most aspies begin to fall behind. It can be overcome with training and/or practice, but that gets harder the further behind they fall. By the time it’s obvious, catching up is HARD.