"New and shiny" implies that there is no real value in the newest tool, that it's just a trend for hipsters to follow.
IMO developers rapidly move to new tools and technology because they are better - simpler, more full featured, easier to use or take a new approach that solves problems in existing approaches.
The "celebrity" suggestion here appears to be that sheep like developers just go and do something ecause some known person has built something. This suggests that developers are stupid. Who has time to learn something only because of the name of the developer? Developers use things because it makes sense to do so.
With that said even with some years under its belt yet the react community is still in a state of flux (no pun intended), and one is signing up for new and shiny for the next couple of years. One should know that and embrace it going in. There is nothing wrong with that. I feel like we are currently in the "walking" phase with React and have stepped out of "crawling". These tools are helping us learn to "run".
A lot of this re-invention happens when a community "celebrity" decides it's time to (yet again) move to the latest new and shiny way of doing state management or data fetching. It's pretty annoying and exhausting at this point to attempt to keep up.