Yes, it has been my experience that (for the most part with only minor tweaks) layouts made using the guides for iPads in filemaker will scale accordingly.
Since the iPad Pro is 2732 x 2048, you may just want to add your own custom guides, given that you'll have a lot more screen real estate, and your buttons and fields will probably look a lot larger without any restyling.
I'll find out soon. The Pro has just been released here.
It doesn't look like the screen size knowledge base article has been updated to include the iPad Pro, but it does have the information necessary to derive what we'd expect the working layout space to be. Note that for the purposes of designing FileMaker layouts, we should think of the iPad Pro screen being one quarter of it's actual pixel count, i.e. 1366 x 1024 points.
I am not sure how you are getting it so early. I have been on a waiting list and they have told me delivery will be 11/23 at the earliest. The Keyboard and Pencil wont be available until next year.
I've got the Pro and I love it. Pity I have to wait 4-5 weeks for the keyboard / cover and pencil.
Yes, the Pro does have more real estate so your iPad layouts will take up about 65% of the screen.
But don't panic. The Pro has a display option of Standard and Zoomed. In Zoomed mode the standard iPad screen layout fits perfectly. It looks very good and it's truely "sausage finger friendly".
It's also about 10 times faster than my old iPas 2 so it will be fantastic for demos to small groups. Better still, when the pencil arrives I will be able to work from the side of the screen, staying out of the viewers line of sight.
I have one. I like it. Pretty fast.
I have one too and update some of my bases for it, it will be nice if we can make or modify some model on it