Could you (or someone having this evidence) post a link to all this?
As to June 2015 being the month the NES alt army started to arrive, you'd have to look at all the giveaways at the time listed May 2015 or before.
You can see him listed as a NES alt in this known scammers thread post 2572 by One FiercePuppy. But you also have 2726 where pimpmonkey acknowledges it and also acknowledged by madth3 in 2727. A trade chat with TimTom92 shows the language similarities.
Then there is the Ninja Giveaway 2.0 in July when all the NES alts were crying about how nobody would trade with them and what bad people we all were for "messing up their trades". But he couldn't keep it straight which trades were messed up with which alts. Look at post 1560 where Raziel360 (another Jun 2015 account) talked about a messed up trade that was actually attempted by comboplayer.
I cannot link this stuff anymore ironically thanks to the scammers but GoG search brings all of this up just open the top 5 threads, but the clincher in my book...
We have an account which hasn't seemingly posted in over 2 years whose only presence on the forums at the time was attempting to trade with people and "just happened" to create a new account at the same time as the army of alts.
So two years later, he makes a post, and it's in this thread trying to make someone who just got scammed look like a scammer. Does that make sense for any normal user for their first post in 2 years? Or does it make more sense if that was an alt of the scammer trying to create a smokescreen?
Just think about it. It should be really obvious that comboplayer is NES.