If that was true, there would be no issue in the first place.
I faced the same issue on my running Arch system and the keyring was not updated/installed first, to insert the new keys. I had to first explicitly install the keyring to continue.
If pacman doesn’t elevate order for keyring inside and since there is no pacman.conf directive to do it, we have to do it manually. That’s what Archwiki article (in the linked post) explains. 
If I am wrong, at least, I’ll learn something new today 