As long as the alt has a good concept and still continue to be developed I am sure alt will stay afloat even has a significant value increase. but we must be more wise and careful in choosing alt.
Yes, altcoins always grow with or after bitcoins. So it's too early to talk about the death of altcoins. The most important thing for the project is a promising idea and a strong team. It is desirable that the project has a working product or at least mpv. I think that if the project has all these qualities, then the project is likely to be successful.