

Technically it isn’t a filibuster,
Depending on how long he is able to go, he could disrupt Senate business on Tuesday, though his speech technically isn’t a filibuster — the chamber is currently in a limited period of debate time for Matthew Whitaker’s nomination as ambassador to NATO.
Per https://www.politico.com/live-updates/2025/03/31/congress/cory-booker-talk-a-thon-00262482
It just behaves as you would expect a filibuster to behave. The standard no-show threatening is still a thing you can do.
I’ll be honest I assume it’s some parliamentary specifics. If it looks like a duck and quacks like a duck, it’s a filibuster to me. Allegedly it isn’t, but AFAIK, it is. It’s what I expect one to look like. It behaves like one. So it is.