Yes, you can purchase Windows 11 pre-installed on a USB drive.
Yes, you can purchase Windows 11 pre-installed on a USB drive.
Yes, you can purchase the physical license that includes a USB installer and an activation code in a package.
It has been a consistent practice. Newegg Link (Windows 11 Home USB) MicroCenter (Windows 11 Home USB) Microcenter (Windows 11 Pro USB) Direct from Microsoft (Windows 11 USB). For the OP, as others noted: Microsoft clarifies how to generate a USB. (Assuming you have another machine to build one)
Apologies for the oversight, I initially believed it was removed. My previous response has been updated. Thank you.
You could obtain Windows 11 at no cost now and then purchase it later with an activation key.