Paragraph 2 really shows a solid understanding of quality game design. I hope they follow it. The first paragraph is also a pretty good overview of what the MM is there to do IMO. The return of environmental and cultural stats would be nice. So would strategies and tactics, but as mentioned they are not necessary for every creature.
The second paragraph of that section states that vampires cannot cross running water under their own volition and cannot enter private property unless invited inside by someone with the proper authority.
Both moving water (which a vampire could fly over) and property (not intellectual property

) are defined with game mechanics for me.
sunlight destroys the vampire after two rounds, as does immersing it in running water for three rounds. Staking the vampire’s heart and then destroying the body also works.
Again, these can all be defined elements in the game. Light, Sun, Piercing, (wood), a heart, the body part of a creature.
vampires will not enter an area laced with the odor of garlic, recoil from mirrors, and recoil from “strongly presented” holy symbols, although none of these three things actually harm the vampire.
Conditions due to foul odors were defined in 3e IIRC. Turning was too, which in this case includes mirrors. The effect might be line of sight, which is one possible definition for why vampires don't hang around in funhouses, not to mention churches, temples, and whatnot.
How close can a vampire come to a mirror or a holy symbol? How much garlic do my PCs need to buy to keep a vampire enemy out of the king’s daughter’s room? How do I know if my PC cleric’s holy symbol was presented strongly?
A lot of this stuff could be more clearly defined. It isn't impossible, but the level of detail does get into certain aspects of how difficult the game is to run and/or play.
Another option, probably a non-starter from both a traditional and commercial perspective, is to present no monsters at all, except for a few examples, and maybe normal animals. The DM is expected to create all the monsters himself, to preserve mystery. This is what I want as a player, I'm not remotely interested in meeting any more regenerating trolls, or drow, or traditional vampires, or colour-coded dragons. I know what they all do, and I'm bored with them.
This would also apply to magic items.
This should be central in the DMG and in the beginning of any collection books, like monsters, magic items, spells, etc.