Well bb is a competition so it should be fair...
and the tittle asked if its fair and I said no.

Was it fair when Connor won half of the prize money last season for not winning the game???

Was it fair when Speidi were given an advantage by watching their housemates for hours on end?

But, BB can change and make the rules at any given moment based on what BB wants, and the houseguests know that going in. That is the main rule of the game. Its the only rule in the competition really, that BB has ultimate power.

^That's different to sabotaging a housemates game

How is it different. Both scenarios changed the outcome of the game, and how people played the game. What Connor and Luke did and said in that room changed people's perception of them in the game. When Luke was shown talking to a modeling agent, it sabotaged his persona in the game. When Speidi saw people talking about them, it changed their opinion on the people in the game, and when the housemates saw Speidi it was the same. All scenarios were actually set up to sabotage specific individuals.

At least here the producers did not set out to attack Topaz. They set out to see if they could shake up the game on anyone who won the next HoH. It wasn't deliberately unfair to her or unfair to anyone as the way someone reacted couldn't be known. BB didn't ask her to talk out loud and reveal her thoughts, she just did it to herself.

I wouldn't be surprised if they did tbh. Either way Arisa asked her for explanations so she would've spilled the beans regardless.

Well then that explains why BB Canada is garbage.