You bring up some interesting points.
With the Department of Motor Vehicles in some or most states, there is a clear cut off date for "antique" plates. However, when it comes to the word "classic", the definition includes the style and design, rather than just the age. You could have a true "classic" or a piece of plastic junk, both produced on the same day. One would be classic becaue of the lines, build quality, and power options, the other would be............well.............just as quickly forgotten as a Renault Fuego. Unflrtunately Chris Craft built a few boats I would not really care to own, mostly due to change of ownersip and the parade of presidents Herb Pocklington has mentioned they marched through one door (and out the other) during the downward graph of financial stability at Chris Craft. On some of the more modern boats, I would look them over for what they are on a one-at-a-time basis for each model. Some would pass the test, some would most likely be set aside, as my preference is for the older "classic" build quality, detailing, and style.
Some of the lines on Avery designs are almost "Gothic" in style, and you can easily call those "classic lines". Age comes into play because some of the provenance associated with a boat is the era in which it was built, with the credibility of the types of resin and construction techniques, power options,etc., so age does matter (too). The Coho series are classics in my opinion, they are good looking boats, the interiors are thoughtfully designed, they are highly functional, they use the knowledge Chris Craft learned by producing lots of other boats and they share common power options with other boats that are also called classics. A classic Coho would be very welcome at any Chris Craft Commander rendezvous, and I think it would get a lot of attention. People just don't see many of them due to the fact that not all that many were built.