Well take arm and x86, plenty of research papers done on these (e.g. the original speculative execution attacks) but they are closed licensing. Were the ISA sp

Well take arm and x86, plenty of research papers done on these (e.g. the original speculative execution attacks) but they are closed licensing. Were the ISA specifications also fully closed (i.e. no reading without an NDA, strict restrictions on any published research even if you did get access etc), then yes that would be an impediment, but practically that's not what we see.