Sometimes very rare winning or losing streaks can happen. Even if there's a 0.01% chance, someone's going to be that big winner. Since the casino's edge on table games is so low, variance can be brutal in the short term. But the casino's edge on slots is between 5-15%, so variance is much lower. For the machines that have million+ dollar jackpots, the slot manufacturer pays out the jackpots, so a casino would love it if many jackpots hit in a short period of time.
Something tells me that the first big winner in this news story might have been an AP working with a team, especially since he won at multiple casinos and only played blackjack. Maybe he's a great shuffle tracker or hole carder, because most casinos would not let people win so much by straight counting. Obviously he's not going to tell the media that he's an AP, instead choosing to say that he's a gambler who just got lucky. The second gambler seems like a lucky ploppy, a dead giveaway is the $150,000 tip and the fact that he played multiple games. APs wouldn't tip so much even after a multimillion dollar win. If I were a manager at the Trop, I would bar the first player (since it's AC, then shuffle often and deal the cards myself since I couldn't bar him). I'd allow the second player to live in a suite and give him a host who would do almost anything he demands till the casino wins the money back (50 yard line Super Bowl tickets, front row center seats at a Lady Gaga concert, chartered flight to Tropicana in Vegas, etc).