The subhead is important in getting the gist of this article "study it now." Meaning the ridiculous amount of research on Twitter was dumb for awhile, but now that it's changing it might be worth looking at.
They also point out why it's not going to happen
Refocusing on studying X won’t be easy. It will require new methods and approaches that do not depend on the large amounts of data that were easily accessible before.
The API access was what made it so heavily studied and the current costs are why this change isn't going to be low hanging fruit for researchers to pump papers out on.