old cryptsetup default is
es-cbc-essiv:sha256. the new one is
aes-xts-plain64:sha256. i don't know that much about cryptography but i assume the standard was changed for a reason.
also there can be found information like:
[...] if your device is still encrypted with the previous (cryptsetup <1.6.0) default cipher --cipher aes-cbc-essiv, more information leakage may occur from trimmed sector observation than with the current default.
so should i upgrade my old encrypted volumes?