Make your own, it's not tough. Also all the 28 pin controller are mostly the same for pinouts so the old PIC16 28 pin parts in the Eagle lib are not too far off. Same for 40 pin.
Regrettably Eagle is very very bad for the way it did libraries and basically impossible to upgrade. Very, very bad lib management! Consider the case where you add a PIC18F4620 component to "microchip" library. If you upgrade to the next version of Eagle you overwrite the "microchip" lib entirely and lose your PIC18F4620. So you'd have to keep your old one, and there's no straightforward way to merge them. Manual copying is quite tedious and even error-prone. Thus Eagle can't really release an updated version of "microchip" nor can you accept someone else's "microchip" lib without kicking out your own changes. As far as I know Eagle is just not updating these libs.
But, let me say I do like Eagle despite the issues. It's very effective.
The conclusion I reached was it's a better idea to make your own "my_components" library, or at least copy "microchip" to "my_microchip" and modify that one.