Hey Michiel - I am also on that flight and because I am on bereavement travel I booked a Business Class ticket from the get go to enjoy smooth and seamless travel.
(Although considering, I should have probably done the same as you - buy Y and upgrade to C)

Anyway - I was not able to select an F seat in rows 1 & 2 as I understand those are just for HONs - but I did have luck to snatch a throne seat in the C class section.
Now, less than a few weeks before departure they have changed the config, and instead of the business seatmap being rows 1 - 2 and 4 - 17, it is only the F class compartment in rows 1 & 2.
Business class Rows 4 - 17 is now being sold as regular euro economy, together with Premium Eco and normal Eco.

Everyone else who had a seat assignment in C was now moved to F rows 1&2 - but I was not moved and i currently have a confirmed C Class ticket but no C Class seat assignment.
I am GGL/Emerald on BA so I do not fly LX that often - therefore I have never seen this kind of practice.
Does anyone know why I was not moved? Is this normal?
What will happen if I turn up at the airport without a seat assignment and their business is already full? I assume I will be downgraded?

Any insight would be helpful as I have to say that both the LX service center as well as the LX social media team are not helpful at all.
Nobody offered to get in touch with the flight editing team for example, to understand what the situation is with the seatmap.

And please before anyone comes for me, keep in mind:
- I am currently in bereavement for a loss of a parent and I am bringing their remains back to Greece - so take it easy on me - it's not the best of times at the moment.
- I know that this is only a 2hr flight at best, but I paid my own hard earned money for this and I do not want to end up getting the "sh*t end of the stick" - it will just create an additional sour taste to an already difficult time.

Thank you if anyone can help clarifying this kind of behavior or even better, provide some advice or help.