Of course it will. I wouldn't do it.
I upgraded my kids iPad mini (don't remember which one but its one of the early ones) to iOS 11 and it's SO SLOW, it's pathetic. Can't go back to iOS 10. Been thinking about writing a complaint to Apple that they killed my sons device with the latest update.
I refuse to update my iPhone 7 to iOS 11 for that reason.
Same with my MacBook 10 inch. I refuse to update to any new OS because the laptop hardware won't be able to handle it. It will be laggy and slow, forcing you to buy a new laptop. It's sickening what they do. I don't play that game anymore. I've learned from past mistakes.... ALWAYS stick to only the OS the device came with.