It's probably not much of an issue in this specific case. If someone doesn't get your email, that's your (the sender's) problem; but if someone doesn't get the government's email, then that's their (the recipient's) problem.
E-Mail was (last time I checked) not an approved medium for delivery of important documents as it does not (per design) have a mandatory receipt of the message being delivered. So a citizens does not need to worry a lot about this for important documents/mail.
(Fax was so popular for public institutions in Germany because it satisfied this standard. It meant it usually was the lowest barrier option and you could rely on it for all (un)important documents)
These gmail postmaster tools seems to exist to make antitrust cases difficult, not to enable other MSPs to deal with deliverability issues.
At the same time gmail is emerging as the number one source of spam for our customers. If our spam fighting is too tight we falsely flag important mail as spam, and this is absolutely unacceptable to customers. As a consequence we have to relax our spam classification for gmail senders, which manifests itself in false negatives from the perspective of our customer.
But to the customers this reflects on us, not on gmail.
It’s just gmails best interests to make other MSPs miserable to operate. It drives our users to them.
And?