I was trialling out a sub macro and originally i was using Backstab... no big deal, everything was fine.
Changed the level 15 talent to Gloomblade, this replaces Backstab.

For the first run this was absolutely fine.
Checked the edit to make a couple of changes and it was still Backstab until another OOC refresh or /reload and noticed it changed from Backstab to Gloomblade... no biggie all works.

Make a change from Gloomblade to another talent which should revert back to Backstab but GS keeps it to Gloomblade and will no longer fire off Backstab as it's not the original spell/spellid.

Tested this multiple ways on Rogue and it keeps to Gloomblade

Not tested the Ret Crusader Strike etc etc

Added the following overrides:

-- Paladin
Statics.BaseSpellTable[231895] = 31884 -- Crusade to Avenging Wrath
Statics.BaseSpellTable[216331] = 31884 -- Avenging Crusader to Avenging Wrath
Statics.BaseSpellTable[200025] = 53563 -- Beacon of Virtue to Beacon of Light
Statics.BaseSpellTable[204019] = 53595 -- Blessed Hammer -> Hammer of the Righteous
Statics.BaseSpellTable[204018] = 1022 -- Blessing of Spellwarding -> Blessing of Protection
Statics.BaseSpellTable[213652] = 184092 -- Hand of the Protector -> Light of the Protector

-- Warrior
Statics.BaseSpellTable[202168] = 34428 -- Impending Victory -> Victory Rush
Statics.BaseSpellTable[262161] = 167105 -- Warbreaker -> Colossus Smash
Statics.BaseSpellTable[152277] = 227847 -- Ravager -> Bladestorm
Statics.BaseSpellTable[236279] = 20243 -- Devastator -> Devastate

-- Rogue
Statics.BaseSpellTable[200758] = 53 -- Gloomblade -> Backstab
Statics.BaseSpellTable[5171] = 193316 -- Slice and Dice -> Roll the Bones

-- Priest
Statics.BaseSpellTable[123040] = 34433 -- Mindbender -> Shadow Fiend
Statics.BaseSpellTable[200174] = 34433 -- Mindbender -> Shadow Fiend
Statics.BaseSpellTable[205369] = 8122 -- Mind Bomb -> Physic Scream
Statics.BaseSpellTable[205351] = 8092 -- Shadow Word: Void -> Mind Blast
Statics.BaseSpellTable[204197] = 589 -- Purge the Wicked -> Shadow Word: Pain
Statics.BaseSpellTable[271466] = 62618 -- Luminous Barrier -> Power Word: Barrier

-- Hunter
Statics.BaseSpellTable[259387] = 186270 -- Mongoose Bite -> Raptor Strike

-- Warlock

-- Shaman
Statics.BaseSpellTable[192249] = 198067 -- Storm Elemental -> Fire Elemental
Statics.BaseSpellTable[157153] = 5394 -- Cloudburst Totem -> Healing Stream Totem

-- Mage
Statics.BaseSpellTable[205024] = 31687 -- Lonely Winter -> Summon Water Elemental
Statics.BaseSpellTable[212653] = 1953 -- Shimmer -> Blink

-- Monk
Statics.BaseSpellTable[115008] = 109132 -- Chi Torpedo -> Roll
Statics.BaseSpellTable[152173] = 137639 -- Serenity -> Storm, Earth and Fire

-- Druid
Statics.BaseSpellTable[252216] = 1850 -- Tiger Dash -> Dash
Statics.BaseSpellTable[102560] = 194223 -- Incarnation: Chosen of Elune -> Celestial Alignment
Statics.BaseSpellTable[102543] = 106951 -- Incarnation: King of the Jungle -> Beserk
Statics.BaseSpellTable[202028] = 213764 -- Brutal Slash -> Swipe
Statics.BaseSpellTable[236748] = 99 -- Intimidating Roar -> Incapacitating Roar

-- Demon Hunter
Statics.BaseSpellTable[203555] = 162243 -- Demon Blades -> Demon’s Bite
Statics.BaseSpellTable[263642] = 203782 -- Fracture -> Shear

-- Death Knight
Statics.BaseSpellTable[207311] = 55090 -- Clawing Shadows -> Scourge Strike
Statics.BaseSpellTable[152280] = 43265 -- Defile -> Death and Decay
Statics.BaseSpellTable[207127] = 47568 -- Hungering Rune Weapon -> Empower Rune Weapon