I’m creating a list of items and monsters that have not properly been scaled for the new leveling/timewalking options. This means you can level and quest in these areas, but if you get these items or fight these mobs they’ll break up the scaling experience.
DRAGON ISLES
The Waking Shores
Obsidian Citadel
Morchok (His Touch of Flame one shots from as high as level 40 and under, can be summoned as low as level 10 and is required for a few different quests that are obtainable from as low as level 10)
[Obsidian Strongbox][Twilight Cache][Twilight Strongbox] (Requires level 60, can be obtained as low as level 10)
KUL TIRAS
Mechagon
Basically all trinkets (Require level 50, can be obtained as low as level 10)
Punchcards (Require level 50, can be obtained as low as level 10)
Weather Alteration Machine (Requires level 45 to use, can be accessed as low as level 10)
[Exothermic Evaporator Coil] (Requires level 45, needed for Weather Alteration Machine, can be obtained as low as level 10)
[Recycling Requisition][Strange Recycling Requisition] (Requires level 45, can be obtained as low as level 10, can contain [Recycled Crawler Manifold] which is needed for the quest Factory Refurbished that you can get as low as level 10)
[Box of Assorted Parts] (Requires level 45, can be obtained as low as level 10)
Edit: Another set of interesting things that could use an adjustment:
PORTALS
To Stormwind
From Valdrakken - Requires level 8. (You can access Bel’ameth portal as low as level 1 and end up in Valdrakken, but the portals from Bel’ameth have no level requirements)
From Tol Barad - Requires level 30. (You can access Tol Barad portal at level 1)
From Dalaran (Broken Isles & Northrend) & From Stormshield & From Shattrath - Requires level 10. (Less relevant since you’d have to put in the effort to get here, still an inconsistency.)
To Valdrakken
From Stormwind - Requires level 10, which makes the “To Stormwind” portal requiring level 8 inconsistent.
Only reason the level requirements even caught my attention was because I was doing some exploring on a low level and they ended up being able to go to certain places but not leave. Another point of interest is that Dornogal, a.k.a current content, does not have any level requirements on the portals.
Feel free to add more that you have found. I will update as I find more.