As for the security through obscurity discussion, I am personally of the opinion that it is generally a waste of time
I am of this opinion as well, especially in this particular case.
Hackers don’t care what version you are running. They don’t even bother to check. Why? Because they don’t have to.
Here’s how almost all websites get hacked:
1. Hack is discovered in some piece of software.
2. Code is written to exploit it and upload a backdoor of some standard other kind.
3. Code is put into a library of exploits.
4. Library of exploits is mass-spammed across the net on every site that the script kiddie can find.
5. After it runs a few hours, kiddie now has a list of exploited sites that he can do what he likes with.
There’s nowhere in that process that requires version checking. Sure, there is probably some targeting involved in the fact that a site runs WordPress, but it’s actually easier and simpler to simply hit every site with a bunch of known attacks than it is to a) check the version and b) then run the attack specific to that version. The second one is an extra request, which is in fact unnecessary. Mass spamming the requests can be done very rapidly, without any need to read from the network connection at all.
So version obscuring is, in the long run, pointless. It prevents nothing.