As far as I know, there's no specific target, nor additional features, the processes here are very simple and really lite, no complications of anything, creating a Mobile App will lead to cronning the app, and scammer can easily take advantage of that.
With that being said, Bitcointalk forum is in good hands, good shape and perfect in all of it's activities, as of today there's no resemblance anywhere, It's simple on a mission and standard of its own.
Don't see any damage to be done not unless if they change the UI or other things upgrade which eliminate how easy to use the forum the same what we are using right now. But the same like other user who disagree with this idea I will also join them because there's nothing to be change here nor to have an upgrade since this is not really needed. Forum is accessible on any device you are using so creating an app will just be additional work for them and it will cost a lot of money to build this one.