I am not sure if this behavior is intended or favored.
Steps to reproduce:
1- Search for anything, here i used "test"
2- place cursor back to the beginning of the line
3- use any bang, here i used !w such that the end result would be "!w test"
4- after hitting space, the bang will show the website it uses and place the cursor to the end of the line.
One argument would be: the cursor placement should not be changed even if a bang was placed as the user might have an additional input to pre-append.
Another argument: It does not matter because the user is going to hit enter afterwards anyway.
Safari/MacOS Monterey 12.3.1/US-CENTRAL