Nah, besides the fact that the crypto-arm thing was there months if not years before (at least looking at the datasheets)
microchip's 16 and 32 bit are not going to die anytime soon.
besides the fact that microchip never really abandon a product, it just forces you to a newer, cheaper pin-to-pin and feature compatible chip by increasing the old part's price, there are dspics that have peripherals that you can't find on more than one or two arm products (for example, sent) and have all the usual advandages of the 8 bitters (simpler architecture, easier to write assembly, predictable/fixed latency) but this also applies for all the other 16bit chips in the market, at least those i've dealt with
pic32 of course is another story. revision after revision it seems like there are more problems than solutions.. too bad. infact i'm forcing myself thtough the ordeal of learning to develop with stm32 efficiently for a reason