The question is in the title:
“Is GIMP3.0 going to make all the Python2 scripts’ functionality lost with Linux OSs’ move to Python3 part of the new core?”
A followup: “And why not?” :^)
So–very–much work went into their development, and they have come to be relied on by so many, it would be a shame to see them abandoned.
I believe the answer is “python 2 scripts will no longer run”.
Python 2 has been EOL for… 10 years? Its time to move on.
Start porting your scripts or talk to upstream about porting.
If they are useful, then it is up to someone. I hear Python 3 is wonderful, you should try it.
The question is more about moving the functionality into GIMP’s core functionality than how to update scripts.
Q. Is there a process in GIMP development for looking at scripts’ capabilities and deciding whether that same functionality should be offered in GIMP out-of-the-box (eliminating the need for a script)?
@gramp Usually, people make a request for a feature on the issue tracker: Issues · GNOME / GIMP · GitLab
Once 3.0 RC1 is released, the public API will be stable and people will be able to port their plug-ins with confidence that there won’t be breaking changes (in fact, that’s one of the last remaining hold-ups. We’re receiving the API to make sure we haven’t missed anything needed). We’re hoping that more people will start porting their Python 2 plug-ins. We’re also updating our documentation to make it easier to figure out how to do that. 
Lats time I checked support for option arguments in the auto-generated dialog was lacking. Any progress made there?
@Ofnuts Hi! If I understand you correctly, you mean for non-C plug-ins like Python correct? If so, that’s been taken care of (second item on API finalization (#11661) · Issues · GNOME / GIMP · GitLab)
You can check the “official” Python plug-ins for examples, but now you can do something like procedure.add_choice_argument () to add a dropdown/combobox or radio frame.
Hi @cmyk.student !
Will gimpfu for python be discontinued in GIMP Ver. 3? I’m afraid that creating the UI in Python script will be very difficult for this.
Hi! Yes, I think gimpfu is, but now Python uses the same API as the C plug-ins. You can see examples of how the UI works now in the /plug-ins/python/ folder: plug-ins/python · master · GNOME / GIMP · GitLab
Basically, you can set the plug-in arguments and then auto-generate a UI without having to make any additional GTK code. See how arguments are created here: plug-ins/python/foggify.py · master · GNOME / GIMP · GitLab and how the GUI is created here: plug-ins/python/foggify.py · master · GNOME / GIMP · GitLab
Of course, you can also make your own GTK GUI if you want. We’ll be making more detailed tutorials once 3.0 RC1 is released and we have a minute to work on things besides the code.
Thank you very much.
Any way I will wait your more detailed tutorials. I don’ t want to make my own GTK GUI.