I think this is premature and a big mistake for Linux.
The costs of distros and the kernel steadily dropping older x86 support over the last few years never causes an outcry but it's an erosion of what made Linux great. Especially for non-English speaking people in less developed countries.
Open-source maintenance is not a obligation, but it's sad there is not more people pushing to maintain support. Especially for the "universal operating system" Debian which was previously a gold standard in architecture support.
I maintain a relatively popular live Linux distro based on Ubuntu and due to user demand will look into a NetBSD variant to continue support (as suggested in this thread), potentially to support legacy 586 and 686 too.
Though a Debian 13 "Trixie" variant with a custom compiled 686 kernel will be much easier than switching to NetBSD, it appears like NetBSD has more commitment to longer-term arch support.
It would be wonderful to develop systems (eg emulation) to make it practical to support architectures as close to indefinitely as possible.
It does feel like a big end of an era moment for Linux and distros here, with the project following the kind of decision making of big tech companies rather than the ideals of computer enthusiasts.
Right now these deprecation decisions will directly make me spend time working at layers of abstraction I wasn't intending to in order to mitigate the upstream deprecations of the kernels and distros. The reason I have used the kernel and distros like Debian has been to offload that work to the specialist maintainers of the open-source community.