That's a pretty thorough debunking, thank you, and you're right that it's a huge leap to connect Aaron Swartz to this (which I've seen no evidence for). I do want to say, though, that it's a pity that the debunker didn't get better responses from believers on Twitter, as there are some reasonable counter-arguments.
Firstly, I'm not impressed by the (lack of) probability calculations. The article concedes that the Reddit user and Ghislaine are both born in December, which has, let's say, a 1 in 12 chance, and also says that there are "hundreds of thousands" of Maxwells in the world, so let's say 800,000 out of 8 billion, or 1 in 10,000. So the chance of these two details both coinciding is 1 in 120,000.
On the other hand, there are apparently 430 million active monthly users on Reddit, so we should expect there to be some December Maxwells in there, but considering the user's interests (US politics) and their use of British English spelling and phrases[0], I think the number of non-Ghislaine accounts with all these attributes would be very low.
So the fact that this Reddit user posts consistently for 14 years and then abruptly stops posting (publicly) right at the time of Ghislaine's arrest does seem statistically improbable. The debunker would have us believe that the account is still active sending private messages and posting in private subreddits (and no doubt has a girlfriend who lives in Canada), but if they're happy to have their activity disclosed like that, why wouldn't they also post publicly saying "I'm not Ghislaine you idiots!" or respond to the Vice journalist, for that matter?
Is it really that hard to imagine that influential people on Reddit would fake screenshots of post-arrest MaxwellHill activity to try to distance themselves from the actions of a notorious criminal? Do we just have to take these screenshots at face value, despite all the incentive to fake them, and the fact that a mod has already been caught out in a lie about whether MaxwellHill lived in or visited Malaysia?
The debunker also claims that someone trying to hide their identity (by falsely claiming to be male) wouldn't be so stupid as to use their actual name as part of their username, but obviously the motivation to hide what you are doing changes over time. When MaxwellHill was first registered, it probably seemed anonymous enough (there are "hundreds of thousands" of Maxwells in the world, after all), but over time, as the account became more influential (and Ghislaine got involved in more and more shady activities, and gave away more and more clues about her identity from her posts) she would develop a need to throw people off the trail by dropping some false biographic details.
I won't go into more details about the stylometry and contents of MaxwellHill's posts, as that is more subjective, but I will end by saying there is nothing contradictory about Ghislaine as a Redditor making negative comments about Trump (which is implied but not cited by the debunker) but Ghislaine in person bragging to someone about being a friend of Trump. It's possible that she hates Trump's current politics, but got on fine with him in a social setting 20 years ago, for example. In fact I suspect that one of her greatest talents is being able to seem friendly and trustworthy to powerful people whose actions she doesn't fully agree with.
[0] https://www.rareddit.com/r/conspiracy/comments/hnfx0r/not_co...