To clear the air up a little I thought it would be good to do a summary:

During check-in, I noticed seat 6A was free again. I picked seat 6A in check-in, and this was the seat that I was placed in! (despite the LOT app still saying 9A)

Heathrow was VERY busy at 4am, so be aware if travelling. The seats next to me were filled (172/186 seats in total!).

I thank LOT for the decent service onboard, and sending the independence livery 737 MAX!