I use systemd-boot so it was pretty easy, and it should be similar in GRUB:
title My boot entry that starts the VM
linux /vmlinuz-linux-zen
initrd /amd-ucode.img
initrd /initramfs-linux-zen.img
options quiet splash root=ZSystem/linux/archlinux rw pcie_aspm=off iommu=on systemd.unit=qemu-vms.target
What you want is that part: systemd.unit=qemu-vms.target
which tells systemd which target to boot to. I launch my VMs with scripts so I have the qemu-vms.target and it depends on the VMs I want to autostart. A target is a set of services to run for a desired system state, the default usually being graphical or multi-user, but really it can be anything, and use whatever set of services you want: start network, don’t start network, mount drives, don’t mount drives, entirely up to you.
https://man.archlinux.org/man/systemd.target.5.en
You can also see if there’s a predefined rescue target that fits your need and just goes to a local console: https://man.archlinux.org/man/systemd.special.7.en
Legal content that violates community rules or instance rules but is otherwise harmless like spam, is kept in the modlog just fine. People don’t generally browse the modlogs as you generally can’t interact with the stuff anyway. No upvotes (more likely, tons of downvotes), no commenting. Not much better than going to the internet archive to undelete a post elsewhere.
More extreme content like CSAM usually gets deleted then purged instead, which is a feature that properly goes in and wipes the content permanently.