There's a lovely new Linux kernel patch series out that's big in working on a major clean-up of the x86 APIC code (or "decrapification" as it's called in the patches) and also bringing up for discussion the idea of killing off x86 32-bit support. It's unlikely the x86 32-bit support will be removed right now, which is "just museum pieces", but as an alternative would be making it SMP-only to at least remove the uni-processor code paths...
While Intel Arc Graphics continue enjoying performance optimizations with the open-source Linux graphics driver stack, the major limitation facing Arc Graphics on Linux right now for gamers is the lack of sparse residency support that is needed for running many newer games on Linux with Intel graphics -- particularly newer Windows D3D12 titles running on Linux via Valve's Steam Play. It's been a long known limitation and will hopefully be addressed once the Intel Xe kernel driver is introduced, but at least as an interim solution there is now "fake" sparse support being implemented...