I have upgraded Laptops running widows 7 to the latest with no real issues save some updates I got. Even put a Samsung ssd in one that is many years old and it is a flyer now. I have also used a Micron 2280 format SSD drive in one and it flew as well using a Sabrent Converter to SATA and it works in a LAptop and Desktop running Win 10 versus the Win7 machines they were
As to your initial question I know it works for Win10 home but not premium, although my research showed that functions in 10 Pro I would never use. When you make the USB it only stores the O/S and leaves everything in place, have never lost a file or anything yet. In fact I used the Media Creation Tool in place on the system and it went right through
On the latter, ok, only the old OS is removed, leaving all else in place. Good. This Win 7 Pro machine already has a 128 GB SSD as the C: drive (boot / OS / most programs) and a 500 GB HD as the data drive "D:", so, no real issues there unless for some reason I want to put in a larger SSD.
I did the SSD upgrade on this machine, a few years back, but with no OS upgrade, as Win 10 was not yet out. IIRC, I used Macrium Reflect to transfer "everything".