There are two HA folk (excluding frenck) commenting on that thread. The first demands than nixos devs should "Just do as he asks", which seems to me like they are very much getting involved in the dispute.

The second only comments to close the thread, and—while they do include the phrase "it's not our issue" in their closing comment—the rest of that comment accuses the OP of bad faith posting, and goes on to misrepresent the issue completely, claiming the problem is that NixOS are doing things that are unsupported (Frenck's objection was to NixOS packaging his package at all in any form, not to anything specific they were doing with it). So again, that seems like the second poster is very much contributing to the dispute, not "not getting involved".

> one way was for NixOS to ask upstream HA to drop the library as a dependency. It doesn't sound like a friendly heads-up to me

I guess a lot of this does depend on how reasonable you think that request would be. I thought the post seemed friendly as it was phrased politely. And I think removing the dependency should be reasonable if HA wished to remain an open source project given the dependency is now defacto closed source (perhaps not technically in licence text, but the author harassing anyone wishing to avail of the licence would seem to nullify that).

> from the thread title.

Title opens with the word "consider". Seems polite to me...