I vote ... MAYBE!
First, you need to also consider a second bit of rules that interacts with the bit quoted above:
In combat, Might can help you with particular applications of Fists and Weapons: if physical force is a very significant element at play, Might will modify (page 214) the primary skill.
Note that this passage is listed under "Wrestling" which makes it easy to argue that it
only applies to wrestling. However, since wresling is largely an application of the grapple rules, and since grapple uses Might specifically (as opposed to Fists modified by Might), AND since the quoted bit of rules seems to be worded very generally, it could be argued that it is not meant to apply only to wrestling. I don't know.
In any case, let's pretend that it was meant to be applied generally. In that case, it could mean that if a weapon was large enough that having enough physical stength to lift it was a significant concern, then Might would
modify Weapons. Yes, that would mean it potentially makes the attack more accurate.
"What? That makes NO sense!" Ok, I kind of agree.
But look at it the other way around -- not that it improves accuracy, but that it makes the attack harder to avoid and more effective when it lands. Does this make sense? Well, yes: if someone swings a telephone pole at me, that's (a) harder to dodge out of the way of, and (b) will have more of an impact.
The key to making this work is to
not adjust weapon rating based on weapon size. That is, let's say a polearm is weapon:3. A telephone polearm is
also weapon:3 (not weapon:6 or whatever you would normally decide on), but requires Mythic Strength to wield. And because it can only ever be wielded by folk with Mythic Strength, it will end up behaving as a weapon that increases Weapon skill by +3 (due to Supreme Strength) and has a rating of weapon:9 (due to Devestating Blows adding to the basic weapon:3).
Note that this is not a license to add +3 to Weapon skill whenever attacking. When attacking with normal weapons, Might does not modify, so you'd "only" add the +6 stress for Devestating Blows. If you want to apply the full force of your awesome strength, you can't use that sissy Claymore; you're going to need a
MANLY weapon!
Or, at least, that's
one way the rules can be read. YMMV.