This did not happen to me. (No cascade to a 3rd person).
Both 1MMs, my spouse and I typically designate pals who have moved their United address to match our homes. We've both been 1K for years, so it has helped 2 additional friends. Last year we flew less. As I was getting 1K for 2024, I changed my spouse to my Million Mile Companion last Fall... He kept his pal as the Million Mile Companion. So for 2024, I am 1K. My spouse is 1K (and the site notes he got it via a Companion). Spouse's pal is just gold from his flying.