There are 386 and 486 open source reimplementations in Verilog (see z386 and z486). As far as I know, existing commercial 386/486 chips still manufactured (yes they exist!) are descendants of Cyrix work, not Intel or AMD. Consequently, VIA may be contractually holding those back rather than Intel/AMD doing anything there.
Thanks for that information! I have been interested in getting x86 produced in smaller nanometer (e.g. <32nm). My project: https://ei2030.github.io/FemtoTX/#about
Edit: It also appears Nvidia might also have an x86 license: https://www.nvidia.com/en-us/drivers/uli-m6117c/
Also, https://www.tomshardware.com/pc-components/cpus/intel-licens... (Caveat: The startup is acquainted with the Intel CEO, so it's rare for them to grant the x86 license to non-buddies.)
"Intel provided Rosaic access to an unknown Atom-class core, which enables the company to build its own custom processors based on x86 general-purpose cores, according to the report. The renowned chipmaker plans to ship Rosaic register-transfer level (RTL) code for the Atom processor core, which will let the startup build its custom system-on-chip (SoC) both at Intel Foundry and elsewhere."
What's interesting is that a startup with limited funds would most likely seek a 32-bit x86 license if a) they don't need more than 4GB of RAM, and b), if they don't want to pay AMD for the 64 bit license add-on. :)