LW even if you are not in it or have not even tried it, many quests in other times are broken, NPCs missing, scenery if off for the quest line. just now with a player in WOD time, has the dark portal quest intro quest to tanaan jungle, i talk to NPC in portal room, get ported to blasted lands and arcmage khadgar is not there, area has a different scenery/doodad set up. minimap shows the circle where he show be. i went thru the portal pn ,y own and end up in BC.
as for doing SL skips, being in SL time, previously if you used this option it only jacked a few dungeons, you could still clear/solo them but the loot was level 50+. you could do world quests, each zone had scatted quests, i was able to grind avowed faction rep, mobs in 90% plus of SL scaled to me.
today took a player put it in SL time, did the skips, when i go to each zone the scattered quests are missing, only mobs in WQ areas scale to me, and area outside that drops WQ status mobs jump to level 50+
i mentioned this in the loot thread, all the players i used at the mixing pools, had completed the small intro quest chain to fill the pool. now only three can do it in LW. five other players even when i take them out of LW still can't do what they once could.
prior to LW, because i had done the DF campaigns using a 70, one of my 20s was able to continue the campaign into azure span, thaldraszus with no issues. i just checked with this 20 hunter who is in SL time (for max portal use), the mobs are scaled to me even outside of WQ areas. all the quests i skipped are still available