I'm sure you fear reading that someone wants the default font back, again; but I do not as there were reasons for removing it.
Now there is still something lacking: you pretty much have to include a font file in your project, because its difficult to in a crossplatform way find some preinstalled font, which all systems should have.
A good first step would be a function that only finds out the directory where font files are stored and returns a string containing the path, for example "C:/WINDOWS/Fonts/". I think there would be some way available to find that out on all OS, as other programs can do that, too. If that gives no security concern it could help people already a little if they want to try loading some random or less random font from there, otherwise hide it inside the second part.
This second step would be to base a class thats the equivalent of sf::VideoMode for font files on that foundation and give only a few common options like getting some monospace or serif or sans serif or handwriting or ... font, maybe also add the font attributes to choose a premade normal, bold, italic, ... font. This class could then have a method to return a filename to be fed to the font class or maybe just also add another constructor to sf::Font to take advantage of information the font finder class internally collected already.