Outside decent connections it's not even remotely debatable unless you go balls deep in either characters lore and feats which is pretty much a one sided stomp in either direction
The difference is, nobody knows who stomps between the two, which means it's still debatable, the debate is just who stomps.
Shit Frieza vs Megatron is more debatable than shit and it's all more on whether you view IDW Megatron feats
IDW Megatron feats that have been firmly bunked, with a speed tier that still leaves him blitzed to hell and back.
Freiza vs Megatron is more ******* worth an episode given two iconic characters from both well known franchises In fiction than running back a ****** not many give that much of shit of coming back especially in comparison to many others characters
Oh, so two characters both being iconic is grounds enough for a matchup. Alrighty then, I guess we should do Robocop vs Sonic the Hedgehog then. It'd have similar levels of connections and debateability to Megatron vs Frieza.
Frieza and Megatron are individually long overdue for a matchup, but they shouldn't fight each other just because of that. Anyways, Nemesis himself still wants Frieza to fight
a Megatron, just not the G1 Megatron. Rather, the Megatron from the Unicron Trilogy, a matchup that treats Megatron as an actual character and not as a brand.
I personally prefer Pyron from Darkstalkers for Frieza (Though I've heard specifically Apex Predator Lex is actually a decently thematic matchup for him, albeit Lex really dosn't need to come back any time soon, and Frieza also allegedly has a pretty good matchup against a Touhou Girl).
As for specifically G1 Megatron, I've heard Char from Gundam is thematic for him, and I've heard that Ridley and Sinestro are also good matchups for him in the event Vile and/or Terumi fight one of their alts instead.