I realize this has been asked a few times, but with all due respect to the history of the difficulties in supporting Linux in the past, I wanted to make an argument for why it may be due time to revisit any past decisions here.
In a previous rejection of this feature request, a twitter thread was linked that dates back to a game that came out in 2014 talking about the fragmentation of GPU support between distributions being a source of constant crashes. In 2023, all major linux distributions now ship with an option to install non-Free nVidia drivers, and the Steamdeck has proven you can now ship AAA titles to Linux successfully and run games with Vulkan pretty easily.
From an audio perspective, all modern kernels ship with Pipewire, which allows for low-latency audio performance for any USB class-compliant audio interface. I've personally got a brand new Apollo USB interface running at 24-bit 96kHz and it required absolutely ZERO setup. Bitwig ships a native Linux client through Flatpak. I opened Bitwig, selected the Apollo interface and was off to the races. It felt easier than a Mac to me.
Without knowing how Rekordbox is developed I can't say how much effort it would be, but I do know that cross-platform development is easier than ever, and there are options such as Zig that can help with cross-compiling a C++ project. Because Flatpak solves a lot of the dependency and distribution issues and Pipewire has mostly solved low-latency audio, the market for Linux audio is healthier than it's ever been, and there's even examples of people DJing with a Steamdeck. Personally I would buy Rekordbox tomorrow if it ran on Linux, since I'm already paying for and using both Bitwig and Vital to produce on a Pop!_OS installation just fine.
Edit: Oh also, Linux support would be great marketing along side the "Freedom through music" tagline.