What is interesting is that I just got booted out of 1A(which I had booked a few weeks in advance via phone) in an LHR-ATH segment that I'm about to fly on Saturday, and I'm an M+B gold. I got a call from A3 but couldn't pick it up. Called later to see if my reservation was OK, and the agent told me "there was a curtain position change(???) and you've been moved to 2F"

Tried to do OLCI, and whole row 1 was occupied. Expertflyer says row1 is occupied, and not blocked.

Very weird... I had a confirmed seat assignment, but got booted out of it. Maybe because I used a gold coupon to upgrade? who knows...

Edit: I figured out why... A3 looks like it's going to start charging for seat selection. On my return leg, in manage my booking I can now select my seat online, and I can see there are 3 categories: "standard, upfront, extra legroom". Right now I can change seats for free probably because I had already booked mine via phone.
In some other greek forums, people(even aegean golds) are asked for money for seat selection. Sample prices are:

Standard = free
Up Front up to row 10 : 2 euros
Extra leg room - 8 euros