Thank you to everyone for chipping in their thoughts on this.
Logan, good article. It gave me a new idea and wanted to see what y'all thought.
If my main goal is to not have all these 404s from unpublished pages and to re-direct the incoming link value to pages that could benefit, what would you think of putting up a noindexed page that links to my top pages that I want to give greater authority to? Then, put in a request to de-index those old urls that have the noindexed (duplicate) content. That would mean not firing off a 404, just showing the same content on hundreds of noindexed/deindexed pages. Given your point about re-directs, chained re-directs and speed for mobile, would that do more for me than re-directing all of these old urls to new pages?
Compounding the problem a little, this particular site has a catalog that comes out twice a year where many product pages are constantly being unpublished. So, even if I re-directed the old unpublished pages to existing urls, some of those might be going away and need another re-direct to add to the chain shortly.
Any thoughts on this appreciated. Thanks! Best... Mike