Not to be rude, but that didn't answer my question.
Taking a look at IBM's Watson page, https://www.ibm.com/watson, it appears to me that they basically started over with "watsonx" in 2023 (after ChatGPT was released) and what's there now is basically just a hat tip to their previous branding.
I think that's essentially accurate even if some work from IBM Research in particular did carry over. As I recall my timelines, yes, IBM rebooted and reorganized Watson to a significant degree while continuing to use a derivation of the original branding (and took advantage of Red Hat platforms/products).
Taking a look at IBM's Watson page, https://www.ibm.com/watson, it appears to me that they basically started over with "watsonx" in 2023 (after ChatGPT was released) and what's there now is basically just a hat tip to their previous branding.