gpg: keyring `/tmp/tmpve_8ubeu/secring.gpg' created
gpg: keyring `/tmp/tmpve_8ubeu/pubring.gpg' created
gpg: requesting key 75BCA694 from hkp server keyserver.ubuntu.com
gpg: /tmp/tmpve_8ubeu/trustdb.gpg: trustdb created
gpg: key 75BCA694: public key "Launchpad PPA for certbot" imported
gpg: Total number processed: 1
gpg: imported: 1 (RSA: 1)
OK
I just updated the GitHub issue you linked above, but to answer your questions:
it is secure, reliable... And will be officially updated?
Yes. It is maintained by two very experienced Debian developers working with the Certbot team.
why not closed the issue? .. and why "nobody official" say something?
I wanted both Debian developers to sign off on the PPA before we started shouting about it. I got a +1 from the other developer this morning and closed the issue.
about instructions certbot.eff.org (eg. #ubuntuxenial-apache), need to change for the standard apt procedure reccomendation.