When it comes to printers, dealing w/ the drivers can get tricky. In most cases, if the printer doesn’t support drivers on your client platform (e.g., Mac), it doesn’t matter if the printer is shared as a networked device, you still need to download and install the drivers locally. And that’s particularly problematic for printers that I would classify as “WinPrinters”. These rely heavily on the underlying OS for feature support. That’s why it may not be possible for the manufacturer to provide drivers for other platforms; the printer is essentially OS-dependent.
In some cases, drivers may have been developed independently, and thus *may* be available on a given platform, despite the fact the manufacturer doesn’t officially support it. Under Linux, the CUPS printing subsystem is a good example. But not being a Mac user, I don’t know if the same can be said of that platform (I tend to doubt it).
So as far your initial inquiry, yes, you can usually convert a USB-only printer to network print (wired and/or wireless) using some form of print server. But you still need the drivers for your various client platforms, either from the manufacturer or third-parties.