Your right the idea of BOM is to remove the onion layers and you don't need Alpha cuts or a HUD. With that the rendering costs come down.
But if some people want to use the HUD there is no reason why they cant.
That's all i am saying.
You have the Omega Applier that allows you to wear BOM textures on existing avatars.
Not everyone will be running to update their avatar for whatever reason.
Me i don't have alpha cuts on my avatar or onion layers, I Created my avatar for BOM. For now while BOM isn't officially released all i do is when i buy a new piece of clothing i create my own alpha for my skin texture (as i have a full perm skin texture). and then put it in with the folder of that item of clothing.
This is because i don't want to create an onion layered avatar.
As i made my avi for me i can wait for BOM to be released.