Oh boy, that memory bus... I'll get to that in a second. First, yes, IBM creates IP blocks that they then license. Maybe I'm weird, but I view that as software - and I also heartily dislike IP block shops. What makes matters worse is how IBM has an awful track record when it comes to these licenses - they somehow always pick a partner that ensures the tech seeing little to no use. For example, you mentioned their memory bus... guess how they did that: they licensed (or sold?) Centaur to a single party, Microchip, who lists[0] a single memory controller with no price and no apparent interest in actually selling the thing. Also, Synopsys - one of those fabless companies that I love so much, is somehow involved[1]... resulting in memory controller binary blobs. It is pretty awesome really, I don't think IBM could have more surely murdered their tech if they'd tried.
Now I'm pulling for them, I actually own a POWER9 machine. I think it is great that they want to get memory controllers out of the CPU - but they've done it in such a way that leads me to believe that it is an intentional sabotage, which would only happen if they genuinely had no interest in an active hardware role.
[0] https://www.microchip.com/en-us/product/PM8596
[1] https://github.com/open-power/ocmb-explorer-fw/blob/6570112a...