After doing /gamerule doTileDrops false and having an ore (not iron or gold) broken by a player in survival mode, the ore still drops XP orbs. As I see it, XP shouldn't be dropped, much like /gamerule doMobLoot false prevents mobs from dropping XP.
To reproduce:
1. Do /gamerule doTileDrops false
2. Place an ore (besides iron/gold)
3. Break the ore while in survival mode
As far as I know this is intended behavior. You can create feature requests on https://reddit.com/minecraftsuggestions. Mod please close.