If this was the case the PSP would have totally stopped having localizations, which it didn't, and the 3ds and ds wouldn't have seen nearly as much success.
This myth that piracy just totally stops software support is just that. Not to mention the fact that new software will certainly require higher firmwares, and henkaku, as others have said, is unlikely to be brought to newer firmwares.
I didn't actually say it will totally stop receiving software support. What i was saying is that if piracy is enabled somehow, localization pubs or indies will second guess themselves if the risk they're taking is worth it. For example, if a game was originally ps4/vita, they might just consider the ps4 only given the small install base,the risk involved in piracy and other things. It is already happening today with some games even without the piracy element. It's another unnecessary risk.
You can cite the 3DS/DS/PSP but those devices have double or triple the install base of Vita that the risk of your piracy can be alleviated somehow if you can sell even to a small percent of your install base. The games you develop for either the PSP or DS is also cheaper as development costs was cheaper those days. You dont have those cushions with the Vita.
Yes, it's unlikely that henkaku will be ported to newer versions but it is still a kernel exploit. Who's to say it won't be able to bypass version checks one day for new software? I'm not really an expert on how the exploit was developed but I still know a bit about software development to make an assessment on how I think it will go from here.