SG's and long neck tenons

Probably need to expand on that: I'm aware that early SG's had some sort of 'box joints', but I'm refurbing a 'Vintage' brand SG and it definitely has a 'long tenon' that extends right across the neck pickup cavity.

I'm just interested to know whether this is a standard feature on modern set-neck SG type guitar's; Les Paul types often make a big deal over this feature.