If a default typ file is introduced I dont think its a good idea to maintain the default style without a typ file. This is not going to work and you will not benefit of the extra value that a typ file can add. Reason is that a map without a typ file only can display a very limited amount of lines. Extended line types are without a typ file are either invisible or displayed as a thin black line, and therefore not useable in the default style file. For example you still can't add bridges or tunnels because this will not render very well without a typ file. So there are two options, either develop another alternative set of styles which can be used with a typ file (something like I'm working on for Lambertus' maps) and maintain the default style file that is used without a typ file, or adapt the default style file and add a sparse typ file in which the extended line elements are worked out.