Fender/PreSonus has recently Notion for iPad. It’s now free with in-app purchases. It works well and supports MusicXML 3.0 as well as the Apple pencil. I’ve been using it since first released about ten years ago.
Yea… I’m not holding my breath. I want it when it becomes available but am not letting this keep me from getting my work done.
Encore is a tool. If I must, I’ll use another. If I need to open an old file, there are ways. Everything I’ve ever done has been exported to MIDI, MusicXML and pdf. Nothing will be lost when I get a new Mac; it will just be a bit inconvenient to convert these files to something else.