I'm running Windows (25H2, 26200.7462). I used the batch file you pasted and tried your repro steps, multiple times (I started writing this comment, in fact). It didn't steal focus. (Edit: See below). I'm quite sure that I haven't had a steal-focus issue at the OS level for many years, and I use Windows all day, every day. I'm also a Visual Studio user.

Edit: I tried it with Firefox and got a repro there. No stealing with Edge.