First off, the mail references far more rust adoption than just Sequoia, but since you bring it up: here is how RPM adopted Sequoia in Fedora-land. There was a proposal, a discussion with developers about the ramifications (including discussion about making sure the RPMs built on all architectures), and there were votes and approvals. Costs and benefits and alternatives were analyzed. Here's a page that has links to the various votes and discussion: https://fedoraproject.org/wiki/Changes/RpmSequoia

Can't you see how much more thought and care went into this, than is on display in this Debian email (the "if your architecture is not supported in 6 months then your port is dead" email)?