Apparently this is true.
The developer made swapping to XAB and left the forum.
Yes and now price of POSTcoin is up 300sat on Yobit exchanger
XAB news
So LiveCoin made it official...
"Due to the fact that developer has left the XAB project and it will no longer be supported, this coin will be delisted from Exchange in 1 week.
We can't support coins without developers due to possible security issues. We can't bear sole responsibility for such coins. So please withdraw your XAB until November 27. Deposit of XAB is unavailable from now on."