They should really implement these. Ashran, Tol Barad and Wintergrasp should replace the arena skirmish event in rotation. These pvp timewalking events should reward normal raid level loot (pvp version of it) just like those regular timewalking dungeon events do. In addition they would reward those marks of honor and bonus honor as well combined with proper amount of artifact power.
Right now, the pvp events are abysmal. The battleground event is good since bg's reward extra honor for the duration, but the finishing quest is pointless. The Arena skirmish event is utterly pointless for everyone as even with added bonus honor, the skirmishes are useless for prestige. The event quest only rewards 1000 honor (which is one honor level) and you don't miss anything if you miss that. There's no gear and the ap is not important either so there's no reason whatsoever to even participate in this event.
Those pvp timewalking events with real adde bonus and gear would make people actually participate in them.
Edit: alternatively they could replace the arena skirmish event with RATED ARENA event with a piece of gear as reward. Skirmishes are really such niche and having an event around them is just... well I can't think of a reason for this event to excist over rated arena event.