I heard that FCP (final cut pro - editing software by Apple) has stopped developing. Any editing software if not updated will become useless in short while. So FCP will not be of much help if they are not going to develop it. Is it true that they have stopped the development? I have heard this especially from people who are working on Adobe.
Your question is simply mistaken on multiple levels. To the best of my knowledge, there has been no announcement about an end of development of Final Cut Pro. FCPX is the current version and still gets updates and it is still a very popular piece of software.
Additionally, even if they stopped development today, your premise that editing software rapidly becomes obsolete without constant updates is also 100% incorrect. Video formats change at a near glacial pace for the tech world. Almost decade old software can still be used comfortably today and often is. Outdated software results on missing out on some interesting new features like hardware acceleration and 64 bit support, but it still gets the job done just fine.
In fact, part of the reason that Adobe switched to their subscription model is because many users would make a habit of only upgrading every 2 to 5 versions of the software. It is commonplace to use software that is 3 to 5 years old or more.
All in all, it sounds like you are probably confused about what you are hearing and even if you are not, there is no reason to worry for some time yet.