This seems way overblown. An in-depth explanation Werner as to why this is most likely not an issue if you're GPG is > 2.1.9 [1]
An (older) example of expected behaviour [2].
[1] https://lists.gnupg.org/pipermail/gnupg-users/2018-May/06032... [2] https://sourceforge.net/p/enigmail/bugs/538/#43ff