It's not the first. Bitcoin Unlimited already tried to hard fork without success.
the BU block earlier in the year was a mistake of adding an extra tx and got rejected in seconds. there have been a few from different pools on different occasions this has happened and no one cared because they all were non consensus ruled blocks. and got rejected. this is nothing new and is exactly a feature of why bitcoin works. rejcting non-consensus rules.
BU's block only got attention because the core fanboys love over dramatising things.
BU didnt lose 13btc. they never had 13btc. it was a reject like all others.(there have been thousands of rejects over the years)
however the bitcoincash block got accepted into their chain and thus makes it a valid first block larger than 1mb
it proves that a network/crypto can handle more than 1mb of data and as such core/bscartels fud about only 1mb base blocks being safe for the internet has been debunked and that if core done this and allowed ovr 1mb baseblock . bitcoin mainnet would also have a block over 1mb accepted in the bitcoin mainnet chain
