In general if there is an expectation of winning then the activity is taxable, so if you win good money at roulette then that will not be taxable because there is no expectation to win long term (no idea how exploiting a flawed game would count in that as a side note).
Right, but the Radonjic case has made it very, very difficult for the CRA to prove
that a reasonable expectation of profit exists in poker. Based on my understanding, they would now have a much easier time arguing that exploiting a "flaw" in a game such as blackjack or roulette (through some cheat or loophole) equates to taxable income than they would in the case of successful poker playing. I think this is why people are getting excited. But of course, as you mentioned, anyone considering changing their stance with regards to whether or not their poker winnings are taxable should consult a professional.