I don't think the core/default Kate editor does the same "write and close the window" like Notepad++. Kate does have pretty cool options for session handling - which helps keep files open that you had been working on, etc...which i understand is not the same thing. But, now that you asked, i wonder if there is a plugin or extenson for Kate that might provide such a feature? I myself am a fan of Notepad++, and install it on any corporate-issued Windows machine that i am given by dayjobs...but at home, its all linux all the time, so Kate comes closest for me. I did see someone else mentioned that there is something named NotepadQQ or something which is like Notepad++ but works cross-platform...so that sounds interesting if true. And, i wonder if NotepaddQQ has that auto "write and close the window" workflow?
Confirmed; just as you noted this functionality from Notepad++ exists in Kate!!! I guess i now am fully going to dive in to Kate even for Windows (nothing against Notepad++, but no need for it now)! Thanks!