With the growing theme of Apple starting to exploit more profitable options by going upmarket (witness the iPhone launch combined with killing off the iPhone SE and 6s) you'd imagine that it might start to make sense for Apple to make a more 'pro' Mini for profit rather than expecting to make money out of the kind of people who would buy a base model Mini and leave it at that.
We could even see a scenario where - if not a press release spec bump - then Phil Schiller is calling the Mini replacement a 'Mac' because it's not so Mini any more. Whatever it's priced at, it'll be no threat to the forthcoming Mac Pro in an effort to get people to drop some money on the new 'Mac'.
Apple would then price the upgrades accordingly and perhaps expect the profits to start rolling in from the likes of developers, professionals, and server users. I'm half expecting any new Mini configuration to be helpful to people who want to rack mount or stack in a server room or under a TV in a home entertainment shelf.
In other words, a move paralleling the loss of the iPhone SE from the iPhone lineup, leaving the cheapest iPhone available from Apple a 32Gb 7 at $449 where the iPhone SE used to retail for $349. In relative terms, the iPhone SE was beginning to mirror the Mac Mini anyway, a product that was introduced to popular acclaim using current parts. The price changed a couple of times in the intervening years, as did the storage, to keep it reasonably fresh, but then Apple dump it from the lineup, offering more expensive iPhones instead.