I have just experienced this same issue, so evidently the bug still exists and should be fixed as soon as possible.
As I was flying, I suddenly started falling. I knew my Elytra was almost dead at the time, so my conclusion was that it had broken. I swapped it for my chestplate as I fell to minimize fall damage, but no Elytra appeared in my hand when I swapped the chestplate from my hotbar. This happened on an iOS device.
I have both DX12 and a processor above 31.0.101.3430 and mine doesn’t work either.