I've come across the the symbols for closed solder jumpers in design libraries, and now I came across one in a design. I get why you might include an open jumper that could be solder closed, but what is the use case for a solder jumper that is already closed in the pcb layer?
In this case write protect is optional. And disabled by default.
Cut the trace if you want to enable it, link by solder to disable it.
Sometimes you have a need for normally closed solder jumpers.
In addition to the specific explanation that @Jeroen3 provided for your example, there is at least one additional purpose of this type of jumper (Note that the symbol can also be reused for more general jumper purposes and not only the solder-jumper footprint)
Serve as a "net-tie" (Term from altium).
If you have say, AGND and DGND , or GND and SHIELD and want to make certain that they are connected together at exactly one point (and not common net which prevents you from using DRC to review the ground separation), you may use a closed solder jumper to do this if the EDA does not have a special element.
Jeroen3 is absolutely correct. As for a common use case, think about it as the option for a (semi-)permanent switch. It's somewhat similar to placing 0R resistors in places you might want to break the connection later.
A company I worked for had developed at least one board where there were 2 of such NC solder jumpers. Both led to input pins on the uC. That board was roughly 9 out of 10 times used for a specific function and the remaining times as a gateway to such boards. Those gateways had a little extra hardware on them, but that extra hardware needed to be tested manually after production.
One of those NC solder jumpers would be cut at the end of the test procedure to indicate both that this was a special board and that the special features were operating successfully. The uC would no longer receive a high-input on the cut line and now everybody including the uC would know the product is safe to be used.
The other line was used in case a board had been modified in such a way it was no longer fit for use in the field. Think of demo-applications and testing rigs. Those boards were no longer fit for sale.
There are probably many, many more (ab-)uses possible.