That's a bit extreme

I would suggest that at the end of each reason, reset their point to whatever point is required to reach their current rank, so that they don't have to stay in a bottomless pit forever, just for the season at worst.

I won't know, I'm six path on s1
But given that their rank don't reset, I expect their points to not reset as well, since there is no trigger to cause it to reset.

Because I don't want two players to alternatively give win to each other.
It is possible even with Xserver, for two player whose rank and level are really similar, they just need to find a time at which arena activity is fairly low and they will be matched up MOST of the time. And if they never lose point, even if they get caught in a fight with another player, they will lose nothing.

Currently two players can give point by each other via win streak (lose 3 gain 4 if it goes by 3s etc), but that's far harder to execute and subject to interrupt from other players, so it's far less of a concern.

They should have an easier time, but not so much so that it can be abused and cheated off of.