IMHO 5E Blackmoor should be mostly classic Blackmoor with sidebars including information for the newer stuff. A sidebar for each of the other newer races and options would be fine. Let each DM decide what he wants to use but have some limited direction for them if they do want to use it.

You could always take out the Sorcerer Class, rename the warlock to Sorcerer. I think Warlocks fit what Blackmoor Sorcerers were meant to be.

It's a thought anyway.