Mojave will still support 32bit. The OS after Mojave will be 64bit only, which will be likely released in fall 2019. I hope that should be enough time to have released a working 64bit build of dosbox before.
https://9to5mac.com/2018/06/05/macos-mojave-32-bit-support/

More problematic is Wine/Crossover, as there is a memory management problem they can't easily fix. From my understanding to circumvent the problem they need to implement emulation in Wine. And yes, I know what Wine stands for (wine is not an emulator). Maybe they will be ready in fall 2019 to have a 64bit wine app, but I would honestly not expect it will run games very well.
https://www.winehq.org/wwn/364#Wine64%20on%20Mac%20OS%20X

There are some more infos about that topic on the wine page, somewhere hidden in an overview of the last Wine Conference. Unfortunately I can't find that page anymore.

The acronym won't even have to change, just the expansion - Wine is now an emulator.

At least for the mac version ;-) I'm really curious but also suspicious how this will work out. At the moment I don't have a good feeling that performance-wise they really satisfiable can fix this.

DOSBox supports 64bit right now on MacOS/OSX it'll just be slower for protected mode games (1993+). No reason to use it until MacOS dumps 32bit....then mabye people will come to their senses and dump Mac.

Yes, they must have updated it some over the course of the last six years. ;)

And on non-x86-based CPUs. Codeweavers have a version for Android, and I'd be surprised if they aren't at least working on including emulation to get it running on the vast majority of devices as most aren't x86. Also Chrome OS, but there are more x86-based machines in that camp.

I'm sure they have upgraded it, but I don't really feel like messing about with CrossOver just yet. In addition to the issues I had with no visuals showing up, I also remember there being some very slight lag that I noticed. When I got Rise Of The Triad going, I could hear sound, when I moved up and down through the menus I could hear a popping or thumping noise that's supposed to be in the game, but I noticed a slight bit of lag between pressing the key and hearing the sound. In the end I simply used CrossOver to run the installer and therefore gain access to the game files, then I imported the game files straight into Boxer. It was quite a bit of work, but I was able to get it done. It was more effort than simply running the Mac versions of the games using the installers that GOG provide for the Mac versions.

Bump.

DOSBox 0.74-2 supports 64-bit only OS X.

Here's to hoping that Boxer might get updated to take advantage of that.

Nobody plays games on Apple! Nobody!

I did write that half as a joke but there is a bit of truth in there.

A very good thing with the DOSBox update :-)

If macOS High Sierra currently supports 32-bit, then why can't we start extracting out the functionality of the libraries and methods that are called to do so, and create a subsystem we control after Apple drops 32 bit support?

Because that's not how libraries work. For one, there's dependencies. Associated connections that could easily be severed. For two, Apple could easily remove the binary code that would allow the library to recognize or integrate.

Further to this, Apple can, and has just outright blocked the functionality of things before.

Well, I don't think this will be happening. The developer of Boxer has been completely radio silent on all channels for almost five years already, the last (minor) update for Boxer is more than three years old, and the last activity on its GitHub was more than two years ago. I don't see him suddenly turn up out of the blue and update Boxer in the next few weeks before Catalina drops.

So, unless GOG has something else up their sleeves, the DOS games here will become incompatible to the latest version of macOS in the nearest future.

It has been pretty clear that Apple conceded the general use PC market to Windows a long time ago, and considers the prime customers for the MAC to be professional high end users..and so it's no surprise it is going to optimize the system for them, and not pay much attention to entertainment functions.
Anyway, the Mac division is pretty much a minor division of Apple nowdays…..it's the Mobile and Handheld markets that are the major earner for Apple. The Mac division is pretty small potatos compared to that.