Yes, achievements can still be earned in the world.
This is not a bug, it's a feature.
This bug occured for me on Windows 10 and Pocket Edition (Android 7.0).
It seems like using other armor trims will unlock the achievement, but not the 8 mentioned in the achievement description.
@GoldenHelmet Yes, but people could just use /setblock to replace the block with air.
Or Mojang could add a query which checks for the players gamemode (e.g. !q.has_gamemode('creative')) which could then be added as a condition for the event - in this case, if the player is NOT in creative mode this event will be triggered. Same results - everyone is happy... but I don't think so that this will be added very soon.
The setblock solution solves the problem for everyone.