Please note that bug 1666124 which should be classified as having severity S2 – "(Serious) Major Functionality/product severely impaired and a
satisfactory workaround doesn’t exist" – cannot be considered a duplicate of an "enhancement". This is not a "nice-to-have feature" but prevents users from using Thunderbird where the use of offline primary keys/"laptop keys" is mandatory, thereby breaking existing workflows, configurations.
The moment Thunderbird 68.x is not supported anymore (and 78.x does still not support this as the previous Enigmail add-on did), the application will have to be blacklisted/replaced by Mutt, Evolution, Outlook, or other alternatives that e.g. satisfy company policies prohibiting the use of online primary/master keys or needs of user groups which take matters related to privacy/security – namely, protection against identity theft – very serious.
In case fixing the above will require (much) more time for whatever reason, the only two options to prevent abandoning existing users are
- the introduction of a compatibility layer which restores the old functionality ("EnigMail-compat"?); because existing users have everything installed/set up already, there are no license problems due to the need to ship additional third-party components
- ensuring that 68.x /is/ supported until back-to-back tests show that there are no remaining (S2) regressions w.r.t. functionality
MZLA Technologies Corporation should have opted for one or both options in the first place and might well have underestimated that breaking existing functionality related to OpenPGP without providing (temporary) workarounds is not taken kindly, because it forces others to invest time and money to put alternatives in place. (Keep in mind that for a non-profit organization, shrinking/alienating their customers/user base has never been a good strategy.)