Great report, Arlenite! Sounds like a classic case of Did Not Do The Research. Someone should take up an offering and send him a copy of Dr. Ramelli’s tome on the patristic universalists. (Although if he read Robin’s much more accessible work and flat ignored large portions of what it was saying, then I wouldn’t waste the money doing so. )
I have never heard a single word about Marcion being universalistic, and am checking back through Dr. R’s index for refs to see if she mentions it. It’s possible he was and she just happened not to say so because she focuses on what the patristic universalists (including Bardaisan, ClementAlex, Origen and in effect Irenaeus) were challenging Marcion on – and that wasn’t it. Marcion dichotomizes super-strongly between the “OT God” of avenging justice which he painted as false and evil in a fashion mirroring many Gnostics, and the “loving” God of the NT; this was the main point of contention from his (proto-)orthodox opponents, even when they were deploying universalistic Christology arguments against him. It is Marcion, not the patristic universalists, who militantly ignored NT evidence of God’s severity, going so far as to provide a heavily abbreviated and edited version of the received texts (incidentally creating the first known canonical list against the unofficial canon of the orthodox party). Origen, to say the least, could have authoritatively cited more post-mortem punitive texts than McClymond does in his lecture!
Still, as I said, it might perhaps be possible that Marcion might have also been a universalist – he denied the real God judges anyone for sin, and his scope of evangelism was certainly much greater than any Gnostic elitism. But even if so, the most that can be said is that he wasn’t much of anything like the orthodox patristic universalists in how he went about it, and they relentlessly hammered on him.
And in fact he tended to teach that those in hades who held to the standards of the OT would remain unredeemed after the offer of Christ’s salvation; so really his only ‘universalism’ was a scope of offered salvation similar to any Arminianism in principle, and offered post-mortem in practice. And only offered post-mortem to non-Jews! Marcion just didn’t believe that the real unknown God of the NT condemned them, but rather that they had been condemned by the evil God of the OT Who set them a law they couldn’t follow thus ensuring their final damnation by the evil God. The good God decides not to even try to save them.
In that sense the universal scope of Marcion’s potential salvation ends up falling to a standard criticism of Arm soteriology by Calvinists: usually Arminians believe in a limited election of sinners to salvation after all, just like Calvinists even though the number of the elect might technically be larger!