Nyte
Fu-ma's Shadow
Explained in further detail here:Well we don't know for sure just yet, but those creepy blue-and-albino anime rejects may have something to do with it. But if it means Sophitia can swallow at least once, we know she's safe.
https://soulcalibur.wikia.com/wiki/Thread:42144
To get right to a source, this is the original reason why people starting calling it a reboot: Okubo, the producer, said it himself. As well as that, he has stated that it's a "retelling of the original Soulcalibur era, adding and changing things". Now, in general if you're going to retell anything and it contains brand new information, that in itself will automatically create a new universe (the New Timeline). The easiest way to explain this to anyone who has trouble understanding it is to think of Mortal Kombat (2011), that game (as stated by Ed Boon) was a retelling of the first three Mortal Kombat games, adding new information and changes, but it also rebooted the series, much like Soulcalibur VI.
No one pulled the phrase "It's a reboot" out of thin air. Okubo has stated that maybe reboot is the wrong word to use, but regardless it is a New Timeline and it's continuity is separate from that of Soul Edge to Soulcalibur V. Reboot, Soft-Reboot, Retcon, whatever you want to call it, it's a New Timeline.
So basically the old rules don't apply if they don't want it to.