Um...while not "OG Windows" I guess, PowerPC was an officially supported and shipping Windows NT 3.51 & 4 target[1]. It was released a couple of years before XP 64-bit for itanic. SPARC was a planned NT port, and while it never happened, it could have[2][3].

[1] https://archive.org/details/NT351PMZPPC

[2] https://www.techmonitor.ai/technology/undercurrent_bubbling_...

[3] Legend has it that the SPARC port existed, done by Intergraph, but for Reasons was never a product.