Even just the lies around required hw updates is enough not to trust them.
SecureBoot looks like a system designed to make it hard to change OS, it has been used by MS for that, MS have a history of user-antagonist actions.
You say the conspiracy was never true, I'm going to need some serious proof.
To be fair SecureBoot is in a way just that: it is intended to only boot binaries that are signed with a key that has been enrolled into the UEFI. The main issue is like almost always how those keys are managed.