The stands typically come with the mount to attach to the TV and then the TV/mount combo just hooks onto the part of the stand that rises above the base unit.
On mine, you can leave off the riser part of the stand and mount the TV to the wall with the included mount so it would likely work with any mount you already have. But then you have an additional mount (either your original or the one that came with the stand) that won't be in use and just taking up space somewhere in storage.
So in other words, if you buy that type of stand just use the mount that came with it and ditch your old one.