I just got my physical copy of the Descent into Avernus, and at the end of the index, under maps, it says; Poster Map.

Should there be a large scale physical fold out map supplied with the book? Or am I miss interpreting that?

I believe at the back of the book there should be a pull out poster map that you tear along a perforation to remove. 

In which case, I've as usual ended up with a duff copy.

About right considering this week so far.

Cheers

Maybe double check, I could be wrong. Does your copy have the perforation strip, suggesting the map has been pulled out? Or nothing at all?

Edit: This video confirms there should be a tear-out poster map: https://youtu.be/H31s4fKCfEQ?t=1053 (the guy has already removed it, but he shows where it should be)

There's no tearoff strip. It looks like the poster was never bound into the book during manufacture.

Then you should look about getting a replacement. You could always contact WotC direct, they're really good about sorting out that kind of thing.

I have the map at the end of my book, but it don't see a perforation where I can gingerly tear it out. It looks as if it were bound there without an easy way to remove it.

Quote from ArchonJonus >>

I have the map at the end of my book, but it don't see a perforation where I can gingerly tear it out. It looks as if it were bound there without an easy way to remove it.

 Yes, mine looks the same.

I can see what might be a very light perforation line but it's I think it's going to tear badly if I try to pull it apart.

Anyone have any bright ideas?

Fold it back and forth several times and very carefully and slowly tear it out. I did that with my ToA and WDH maps

Yes there should