I go back to what I said ages ago. We should enshrine the terminology. Vintage Motocross is Pre 1975. Then we can have Classic Motocross or some other similar name - 1975 to 1985. And Post-Classic or similar - 1985 to 1995.
If a club wants to be Vintage only, all power to them. HEAVEN for example might cater only to Vintage and Classic classes. If there's enough interest, someone could start up their own Post-Classic club, call is HELL or something. If you're good you'll ride an old twin-shock but if you bad and mean you'll be on a nice 89 YZ....
VIPER might run classes for Vintage, Classic and Post-Classic on one program. Who knows.
But Vintage is the yardstick. It started the whole thing and it's worth preserving for what it means. Pre 75 dirtbikes. Everything after can come into 'the scene' but in its place with its own philosophy. And let's face it, eventually the Post-Post-Post Classic class, Pre 2005, will be cool cos it'll have the first of the new gen 4-strokes in it.
Once you've got these divisions, it's up to clubs and individual to vote with their feet. It's silly to expect any club, eg HEAVEN to cater for every possible class for ever. Add the new classes if you wish, or if enough people want to, create a new club catering to the newer division.
Doesn't sound so hard to me.
Vintage is Vintage is Pre 75. End of story.