DosBox 0.75.0 was released 2020-05-06.
* Upgrade to SDL 2.0
Other changes are here: https://dosbox-staging.github.io/v0-75-0
Well, this isn't an official DOSBox release, and I don't see a reason to move to a forked project when the original software is still being updated (albeit slowly).
If you want this in FreeBSD I'd suggest you make a new port for it.
I agree with MAINTAINER. To avoid confusion, it is better to create another port if we think it is necessary, although I would find more interesting to contribute the changes upstream.
A commit references this bug:
Date: Fri Aug 21 09:30:38 UTC 2020
New revision: 545581
Add emulators/dosbox-staging - DOS/x86 emulator forked from DOSBox
I've renamed binary and man page to avoid conflict with emulators/dosbox.
PR: 246318, 248253