I'm not qualified enough, to thoughtfully analyze the results of this paper, but it should be pointed out, that almost any external impact causes metabolic shifts.
As already mentioned, this setup defeats the whole purpose of encryption: the key is stored near the encrypted partition.
However, it is still possible to get _some_ degree of protection with automounting encrypted drives:
You can setup SecureBoot with encryption keys stored in TPM.
Under SecureBoot security assumptions (motherboard firmware and TPM chip don't have backdors, etc.), this setup will release encryption keys and decrypt your drives only if your OS wasn't tampered with.
Surely, it may be a bad idea, to be _reliant_ on GitHub entirely, but in the world, where supporting your own infrastructure is so expensive and time-consuming I think, that GitHub is a acceptable option.