The installer-button I agree, but the (previously) Add/Remove button doesn't if I'm correct.
It depends entirely on the installer in question. For instance, many MSI-based installers will let you add components, remove components, etc, from an application (eg, MS Office, Visual Studio). "Add/Remove" is probably still the best name for it, or "Modify/Remove" perhaps.
The "modern"-style Add/Remove applet in Windows 2000 and later do display separate buttons for Modify, Repair and Remove (IIRC), for applications that support them. If I find a bit of time in the next couple of weeks, I may submit a patch to support that in the Wine applet.
Cheers,