Here is a compilation of all the info from other threads. Most of the info is for level 20 but might be applicable for 19s or 29s. I have not tested everything myself. Tell me if any info is wrong or missing.
Available for f2p (normal):
- Chromie time seems to be grandfathered for some f2p. No idea what the conditions are, if its not available to you, you can't get it. p2p can still get it by leveling a character to 50.
- Artifact weapon and +5 ilvl artifact relics
- TBC dungeon gear with sockets and +2 stat gems.
- Epic upgrades are ilvl 27
Available for f2p (overpowered):
- Cogwheel gems. Scales to +10 secondary stat. (not sure if patched)
Grandfathered:
- ilvl 59 non azerite Warhelm/Facemask/Cowl/Hood if you did the quest before nerf. New rewards are lower ilvl
- +14 ilvl artifact relics if you have already added it to your artifact weapon. Now has minimum level requirement
Nerfed / Patched on live:
- Heart of Azeroth. Requires level 40.
- Azerite chest. Has higher level requirement
- Legion class hall vendor greens. Has higher level requirement
- ilvl 44 legion gear. Is now ilvl 25, even for previously obtained items
- Rares near apexis crystal assaults gave ilvl 44 items. Nerfed to ilvl 25.
- TBC vendor gear with socket. Has higher level requirement
Nerfed / Patched on PTR:
- Azerite head and shoulders have higher level requirement.
- End of legion zone rewards Valsharah/Aszuna/Highmountain/Stormheim nerfed to ilvl 25.
- First few garrison mission glove and ring nerfed to ilvl 25.
- Remaining rares near apexis crystal assaults that give ilvl 44 ring/neck/cloak have level 40 requirement.