Why are name_tag and nametag different ID items?

Unresolved bug: ID changes left behind legacy IDs

The ID changes from this beta are a great step to parity, but now duplicate items exist.

All items that changed their ID have their old ID still as a valid value, eg record_mellohi alongside music_disc_mellohi.
This affects both renamed items and items which got split up (dyes, boats, spawn eggs).

Affected items:

• Scute
• Enchanted Apple
• Dark Oak Sign
• Boat
• Lodestone Compass
• Raw Cod
• Tropical Fish
• Cooked Cod
• Dye
• Melon
• Glistering Melon
• Spawn Egg
• Fire Charge
• Empty Map
• Carrot on a Stick
• Nether Star
• Firework Rocket
• Firework Star
• Iron Horse Armor
• Gold Horse Armor
• Diamond Horse Armor
• Leather Horse Armor
• Raw Mutton
• Cooked Mutton
• Popped Chorus Fruit
• Totem of Undying
• Music Disc - 13
• Music Disc - Cat
• Music Disc - Blocks
• Music Disc - Chrip
• Music Disc - Far
• Music Disc - Mall
• Music Disc - Mellohi
• Music Disc - Stal
• Music Disc - Strad
• Music Disc - Ward
• Music Disc - 11
• Music Disc - Wait
• Music Disc - Pigstep
• Banner Pattern
• Name Tag