It seems to me that there's a likely pattern in this because as you have said, Penny bets are the most wins on the record but that could just be a coincidence though, anyway congratulations to the winners.
It's most likely a coincidence as more bettors can afford to place hundred penny bets to sustain losses on slots. On the other hand OP picked them randomly so you can't always tell if they're really lucky or not.
Wow, they are so lucky, hoping that I can earn good profit as that but in my entire gambling experience before I never win x3 and above, that is how unlucky I am so I already stop gambling because I am just wasting my money and time on it but sometimes still playing when I am bored, so this gambling is for entertainment only for me. There are so many lucky winners that I have seen in a comment, congrats to all.
That depends on the game you're playing and what strategy you prefer (low/high multipliers), most if not all of the wins posted from OP are coming from slots so it's not surprising to see high multiplier wins.
Anyway these hundred multiplier wins are like the tip of the iceberg though once you've played long enough you'll eventually experience x1000 multiplier wins.