Bedrock Edition removed blocks/Metadata variants

Blocks resulting from extreme data values
The majority of these blocks were likely never actually meant to exist in-game, and occurred only due to the game handling extreme metadata values as it would those in usually attainable ranges, resulting in strange blocks with traits arguably analogous to garbage data.

Seamless stone slabs
This slab variant existed in the game at one point.

Six-sided blocks
Bedrock Edition had a handful of versions of "pillar"-type blocks which used side textures on all six sides. These were effectively removed in an unknown version, forcing them to appear identical to normal such pillars, either by changing their models to that of the normal y-axis pillar or just directly changing them (which method was utilized is unknown).

Weird piston


The "weird piston" block existed for a period of time in Bedrock Edition, but with a much different appearance from the weird piston known from other editions.

Granite, polished granite and diorite bells
Upon their introduction to Bedrock Edition, bells using the textures of granite, polished granite and diorite also existed. They could only be placed by commands, but could also be found in villages.

It is extremely likely that these were the result of the bell being incompletely programmed. The bell can face four directions, and at this point there were four different types of bell (the stone bell alongside these three), which would correspond to the four orthogonal facing directions. Since at this point granite and diorite were stored as data value of stone, it seems reasonable to expect that these would result from drawing from that data value of the used stone texture. Attempting to place a bell with data value 4 or above would fail; there were as a result no polished diorite, andesite or polished andesite bells, as these would not have any facing directions to correspond to. As they later spawned in villages, this would also imply that these were intended to be directional bells.

Bell-less Block
There had been an unused bell which consists of the stand without a bell. This bell cannot be rung, but it will drop a normal bell when broken.

It was merged into the normal version of the block in an unknown update. But however you can see this weird block if you break a normal bell when the game lags but you can't interact with it but when the game updates (remembers what blocks were broken/placed) it will disappear.

Locked Smoker, Blast Furnace, Lectern, and Barrel
There were also several unused blocks which were in a locked state. These blocks cannot be opened or used by the player (their GUI does not show up, but the player hand can still perform an action).

It was merged into the normal version of the block in an unknown update.

Smokeless Campfire
Campfires updated from beta 1.10.0 to 1.11.0 did not produce smoke particles because campfires in 1.10.0 had no functionality. Their difference in the code is not known.

It was merged into the normal version of the block in an unknown update.