In a video I saw from GenCon, they're playing on some sort of mat or playing surface. Will that sort of thing be available from FFG or was it just from GenCon?

I have never seen any of the GenCon demo mats from any of the games become available afterwards. Most of them are just paper anyway not sure if this year was or will be any different.

But FFG have increasingly been doing playmats for their games - ANR, GOT2.0, SWLCG all have playmats - so they'll probably do some for AHLCG?

There are other playmats which do make it out for sale though, for Game of Thrones, Netrunner, and Warhammer 40,000: Conquest, possibly others. I have a feeling this game will be successful enough to spawn a play mat, which might have the knock-on effect of causing a LotR one to be produced for sale as well.

yes of course there will be playmats. But the question was about one specific playmat. LotR has playmats just none for retail, yet.

for what it's worth, the question was about playmats in general (my bold below)

In a video I saw from GenCon, they're playing on some sort of mat or playing surface. Will that sort of thing be available from FFG or was it just from GenCon?

You can already buy play mats from Ultra Pro, so you if you insist on having a mat you can have a mat.

Sure and you can make any playmat you want at sites like inked gaming. Still it is nice to have official game-specific playmats.