No and no. I suppose you could make a feature request (see FAQ).

Or is there a way to setup the Window similar to 8.4.2 to avoid this duplicating hotkey issue?

Note that in earlier versions, e.g. 8.4.2 as you suggest, there are only unique choices for 1,2,3,4,5,6,7,8,9,0 as a maximum of 10 files is presented, and thus the Enter press is not necessary to activate one of them:

And still in 8.4.4, if one has ten or fewer open tabs it will not require the additional Enter press, as Peter’s trial earlier shows.

From your screenshot, there are 2 possibilities for 9 in your list, 9: new 8 and 19: new 28. Since Notepad++ doesn’t know which you intend, it is waiting for you to either press 9 a second time (to move the selection highlight to new 28) or press Enter (to activate new 8).

Steps to reproduce:

Uninstall NotePad++ 8.4.4
Install and load NotePad++ 8.4.2 (64 bit)
Open 20 files.
Click the first file.
Press <ALT> + W
Type a number (I chose window #9) by typing “9”.
In 8.4.2, it jumps immediately to window 9.

Install and load NotePad++ 8.4.4 (64 bit)
Open 20 files.
Click the first file.
Press <ALT> + W
Type a number (I chose window #9) by typing “9”.
It HIGHLIGHTS Window #9 in the Windows list but doesn’t “jump” to it until I hit <ENTER>.

I cannot replicate. With v8.4.4, with four files open, if I type Alt+W then 4, it goes to the fourth window in the Windows menu list, without hitting ENTER, just like it does in previous versions.