It's complicated. Oliver2002 had posted a video explaining it once, but sadly it has been put on private by LH.

TLDR: Amadeus theoretical seating assigns seats based on many factors such as preferences, status etc. Experience report: Some seats that were available for me as a *G weren't available for my friends (FTL and no status) at OLCI, specifically that were the exit row seats in the A321. This is purely anecdotal based on my experience (and I haven't flown that much lately, so beware), but *G most certainly is respected in the system rannking, but I don't really know all the details. Maybe they are open for you at OLCI, maybe not. However, you can always ask nicely at the Check-In desk and maybe you'll get lucky