There are "clipboard managers" that will internally copy the last copied thing as best it can from the clipboard owner, and then when the application exits, will mark its copy as the clipboard owner going forward. If you aren't running a clipboard manager, then yes, nothing will happen.
Some programs (such as xterm) will also use "cut buffers" (in addition to the primary selection, which is what is usually used for the middle button paste) which are retained even if the program is terminated. (Cut buffers are properties of the root window.)
The same thing happens with normal ctrl c + ctrl v. One of the oddities of the Linux desktop of X and Wayland is that for some reason the display server is also in charge of letting people use the clipboard instead of it being done by a dedicated clipboard service.