I just want to sure that as many zeds as possible are kept on the road for as long as possible, Otherwise part are going to become difficult to get or uneconomical to manufacture. That's my only take on it...
In the uk there are a lot, and I mean a LOT of cars over 20 years old on the road. Most wouldn't be classed by their owners as 'classic' cars.
Ask AI to look at the 'how many left' database and it says there's still 12,000 mk1 ford focuses taxed and mot'd. Looking at old VW Golf and it says there's 30,000 remaining actually taxed.
There's a lot of people who'd fall into that 20+ year old group. No chance the country could afford to give them all a tax discount. I suspect there's more chance the gov't will reduce the current discount scheme rather than expand it.