I think basically every claim there was wrong wtf
The Deceptigod is an amalgamation of thousands of Decepticons and there's no real indication its power extends beyond that, it doesn't even manage to damage the one single planet they're all on in any notable way. D-Void itself is a sentient universe, but harming this extension of itself is in no way universal. Even taking this at face value that injuring the D-Void, which really isn't even a physical being anyways, makes him universal it would be a tremendous outlier contradicted numerous times just in this one author's run.
Note: he is talking about G1 Marvel comics Megatron here who....has never even heard of the Grand Black Hole and the Singularities. It's also completely insane to equate the multiverse destroying black hole created via extremely specific circumstances to just any random black hole, from a bio written decades before the GBH was even a thing and that was just referring to generic real life black holes.
He's scaling Cybertron being launched out of orbit in the Marvel comics run specifically to Megatron individually to get him to solar system level, which isn't even suggested by the comic at all.
This is true (or close to it anyways) since Alternity Megatron actually has these multiversal & higher dimensional feats however
Not only do we have no information suggesting Master Megatron was ever part of Alternity Megatron's hivemind, he is just flat out not stronger than Primus, even the individual Primus in the show.
With the Omega Lock, a portion of Primus' power, he is still beaten by the planet leaders+Optimus...who are still powerless to close the Grand Black Hole on their own and need Primus to do it. It's just Galvatron boasting because he's geeked up off the God Powers, there is no reason to take it at face value and his actual feats with said power are already very respectable, there is no need to wank or take it out of context.