Do you think that latest features in Facebook app, Facebook Messenger and Whatsapp, will succeed in rendering Snapchat obsolete?

There is a space for all these products, the audience and users of all these products using it to meet different need and purpose or we can say different way of killing time. As long as these products adapt changes and do advancment and inventions, these products will continue to revolutionize the market. As long as they have money and the best brains in the world, all these products will survive.

Snapchat is a product that have more fun and serious element loaded, and there is an audience loves snapchat than all the other three product. whatever the features that we are saying is taken from snapchat and snapchat have firstcome prefrence in the market and these featuers fits perfect with snapchat than any of the other 3 products. so as long as snapchat meets the users requirements these products cant kill Snapchat. 

With changes is like with new shoes. You need to wear them to get used to. Same is with FB changes. For first sight they look horrible (my opinion) but by time it's so natural like pressing enter while you're sending a message.

I am not sure if there are plenty of people using FB stories (don't know direct statistics) but Snapchat won't be excluded at least not for now.  

Not everyone is Whatsapp fan so obviously not everone uses app and stories. Not everyone has FB profile - same as above. As we know there's no need to have FB profile to use Messenger. 

Conclusion - app updates will change every month (or more often). Depends if we're crazy about new features or not.

"Older generations" like to stay with what they already know. 

no i think it's useless  and they have to think more creatively 

I have no idea, but for this to happen we need to consider which users segments are taking advantage of those services offers. And for what I see there´s a market for them all considering the wide user's segments, regarding age, usability, etc etc

Honest opinion:

If Whatsapp scaled their app with more features like Messenger and Snapchat.

It would beat them both