You can see that on his shop , if GG is compromised too then this is most likely a TOR exploit.
Not sure why else would he change his PGP key tbh.
EDIT : Checked TMG thread , its a new encryption subkey and its automatically signed but am staying away for a while anyways.
P.S I have a copy of his key which i used 2 month ago , was set to RSA 4096 and set to expire on 23/1/2018. :/
When was their previous PGP key going to expire?