Infinitely? Yes.
Temporary? No.
When a BiS twink dings into next bracket, they have to spend time and money to become BiS again. This provides non-twinks a cooldown period during which the twink is not PvPing.
Xp-off twinks staying BiS in any bracket permanently are not providing non-twinks that cooldown period. Twinks are going to be in that specific bracket in a month, in a year time, because of a ridiculous gear advantage they have over scrubs who join PvP Instances half naked and expect a tie on a silver platter. So while the first step is definitely
and that suggestion should be upvoted to the top above all else, it is not enough for twinks and non-twinks to actually meet in the middle. Every bracket has a such high end gear that is still absurdly higher than a baseline. And while such high end gear is great for wargames and WPvP, it is a bane of casual Instanced PvP, and should be brought in line with a standard heirloom baseline provided in that given bracket below max level, which
would take care of