If that release gains network consensus or exchange consensus it will become the primary fork and everyone elses transactions will become orphaned.
Unless there was some change to open source and p2p networks recently?
It's not that simple.
It's not like a vending machine where anyone can walk up and insert a coin, it's like a concert stage where "anyone" can play music, subject to preapproval. Gaining the approval is the hard part. Anyone can attempt to fork, but one of two things has to happen:
1. You get approval from the person/people who own(s) the Paycoin repo on Github to approve your fork, after which all people using that source code now use your version; or,
2. You take the code, change it, and release it yourself. You then have to convince people to download and use your software. Once enough people convert (i.e. consensus is achieved), your software will be the official version.
This means you either have to convince the Paycoin devs to accept your fork (which definitely would not happen if you were trying to take away their ownership/control of Paycoin), or you have to manually convince tons of people to trust your code, download it, and use it. But guess what? Nobody would migrate to the software -- for a multitude of reasons -- mostly because of the fact that the act would seem super sketchy and none of those fucktards would be able to decipher the difference in the code. Compound this with the fact that it will be a direct power play against the current devs (if it weren't you would've just gone through them to make the changes), and you have another clusterfuck of insanity on your hands.
Cryptocurrency isn't as decentralized as you think it is, especially when we are talking about Paycoin.
However, there is one way you could get around this entire system: create an entirely new "Paycoin" community, beginning with your source code. In order for this to work you would just do the second option above and then, rather than convincing the old paycoiners to move to your software, you just convince new ones to join your Paycoin system. This might work, especially considering how many people want the original controllers of Paycoin to die in a pit of fire, but it would still be difficult -- honestly who the fuck would want to deal with Paycoin at this point?
Personally I would advise nobody to invest time, money or effort into Paycoin. There is nothing to gain and everything to lose.