Apple's new silicon is arm64 and virtualization support is very limited:

• Virtualbox has indicated they're not interested in supporting arm64
• VMWare is working on an Apple silicon compatible product, but has already given up on x86 support
• Parallels has a product (at $100 per year) that supports virtual machines on Apple silicon, but it's also limited to arm64 software

Running MediaWiki-Vagrant on the new Apple hardware thus requires an arm64 guest operating system.

That in itself is not a massive problem, as it is perfectly possible to build an equivalent arm64 debian stretch box like the ones we're using on x86 architecture.

However Wikimedia's apt server only supports & serves amd64 & x86 packages.
While it's possible to run an arm64 box, we can't currently install the required software via apt.
It would be nice if we started to support arm64 packages - especially the most common ones (like php (fully supports arm64) & elastic (the version we currently use works on both architectures, 7.x has separate builds for both architectures))

TL;DR: MW-Vagrant works just fine with Parallels on Mac M1 (confirmed with these workarounds), but our apt repository needs to serve (the relevant) packages in arm64 as well.