Intel has provided 5-level paging support to the Linux kernel for nearly a decade to provide larger virtual and physical address spaces as memory sizes continue to expand. As early as Linux 4.12 in 2017, the 5-level paging kernel side bit has been uploaded to upstream and enabled by default in Linux 5.5 in 2019.
Intel CPUs have supported 5-level paging for some time (starting with Ice Lake), and AMD CPUs have also supported 5-level paging starting with Zen4. Therefore, the Linux kernel may move towards enabling level 5 paging support unconditionally in x86_64 kernel builds.
Intel is working on enabling level 5 paging support unconditionally in the Linux kernel. This will expand the virtual address size from 48 bits to 57 bits, allowing up to 128PB of virtual memory.
Intel engineer Kirill Shutemov recently released a series of patches aimed at removing the "CONFIG_X86_5LEVEL" Kconfig build-time option and always enabling level 5 paging in new x86_64 kernel builds.
As a preparation, remove CONFIG_DYNAMIC_MEMORY_LAYOUT, making SPARSEMEM_VMEMMAP the only memory model."
In practice, this doesn't mean much, as most Linux distribution vendors ship their kernels with CONFIG_X86_5LEVEL enabled, but it's one less switch and a sign of the times that upstream kernels are catering more to the needs of modern hardware.