Time for an Audit?
So the assumption being that it's open source so everyone can read the code, so there's no point in checking it / hey what the heck, it's Friday syndrome, let's go / it's from a Uni, it's probably fine. This happened with Netgate and Wireguard which nearly ended up in BSD. It's also not the first time that something dubious has sneaked in - Canonical found that out with crypto miners being sneaked into snaps. Thank goodness they have an Ubuntu Security Team...
I think we have to face facts that this is going to become more of a problem with time and, yes, you're going to have to check the code prior to it being released. You could use automation to a certain degree but in reality it's an independent audit that's going to minimise this.
The bigger question should be how many commits have sneaked through without anyone noticing? Kind of like the sudo privilege escalation vulnerability that sat there for years. Accident / intentional, does it matter? I would imagine some of the best backdoors would come with a healthy dose of plausible deniability.