PM really doesn't need to get images directly from the card in order to be useful. You should be able to pull images in from the Camera Roll on the device and resave them in your app sandbox. I would think you'd be able to rename, apply metadata, etc. there. After that, the trick is getting the images from the device to the desktop OS - with iOS 11, it could be as simple as a folder in iCloud.
There is a very ripe market for an app that can do something like PM on iOS, and Adobe can't stop shooting themselves in the foot trying to figure out what Lightroom Mobile is for. Just when a bunch of pros settled on LR Mobile for doing fast triaging and rating of photos, Adobe ruined the app interface and took away the fast rating feature (supposedly temporarily, but it's been a month of constant anger from effected pros with no response yet).
While new photo processing apps have been coming on the scene with startling regularity lately (Luminar, On1 Photo RAW, Topaz Studio), the thing that will really put someone over the top is getting a useful subset of features on iOS for a reasonable price. I'm not averse to subscription for the right capabilities - Adobe's problem is they're using Mobile as part of the subscription carrot, believing that the Desktop apps are the main attraction, much like newspapers gave away web content/ads believing that print was their "real" product. You don't want to emulate the newspaper industry.
The first player that comes up with a mobile product that integrates seamlessly with the desktop (while not necessarily having every feature, especially at initial release - just the removal of particular pain points) and provides a better way of taking the drudgery out of some of the process will get a lot of business. I think that PM, by its nature, is the obvious product for this role, since you've never been about photo processing - before Lightroom Mobile came along, I did all my flagging in PM before importing to Lightroom (I even set up the shortcut buttons on my Wacom tablet to flag/unflag in PM). I still do my import and metadata editing in PM now, but would really like to move that whole process to the iPad Pro so I can do it anytime/anywhere without carrying a laptop.
Somebody is going to make this product - there's a market there for the taking, and a growing chorus of people who give Adobe a few bucks a month (at least) but aren't particularly happy with them. With all of the other DAMs coming (including yours?), PM has the opportunity to be the universal front end that feeds imported photos and metadata to a whole range of cataloging and processing apps, both on desktop and mobile.
