[Mozilla Enterprise] Firefox add-ons news

[Brian Drake]

On 5/2/19, Romain Testard <romain at mozilla.com> wrote:
> Mozilla has recently upgraded the signing
> <https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/Distribution> for
> Firefox extensions and themes to provide a stronger signature.

I followed the link given, but it did not give any information about
this signing change, let alone why it is so important that it might be
forced onto ESR 68 users (see below). Is this documented anywhere?

> While we expect to support the old signature format on Firefox ESR 68
> through its end of life, we do not guarantee it.

If this change is also applied to ESR 68, it would be a change that
reduces compatibility. I was under the impression that changes that
reduced compatibility would only be made in response to critical
security issues, since the whole point of ESR is to have a stable
specification. But this does not seem to be a critical security issue.
What am I missing?