You can make pull requests there to add parts to the core parts. You can request new parts there as well, but here in the forums is probably better.
The lack of text in pcb is intentional. To remove such text you must modify the part, without the text in the part you can add the text in the sketch without modifying the part. Nothing to stop you from making a part with the text added, it is just non standard (and thus shouldn’t be added to the core parts repo.) If you are interested in making parts these two sets of tutorials apply to the current version of Fritzing many of the others are for older versions.
schematic Inkscape plugin (very useful for making schematics!)