It's the right thing to do. Windows isn't nearly as stable or reproducible as a testing platform anymore and I imagine it's a PITA to handle for benchmarking dozens of not hundreds of hardware configs.

Of course they'll still do those Windows tests, not suggesting they won't, but Linux may become a more useful benchmarking platform for reviewers thanks to the control and automation it provides.

A whole host of configurations can be quickly booted and tested on a benchmark suite to confirm performance of older hardware and provide context, whilst newer products can get a bespoke review on all platforms. If a new benchmark game comes out, it'll be way easier to insert into the Linux setups than Windows.