RxJS author here. We on the RxJS team have never called RxJS FRP as we do not have a continuous notion of time, instead we have a notion of virtual time. That and we do not distinguish between events and behaviors as they all are Observable objects.
It doesn't seem to be very related. Virtual time as defined in jefferson's seminal paper is a variation of Lamport's virtual clocks used in distributed discrete simulations; it is the analog of virtual memory.
The name clash wouldn't be such a big deal (systems is far away from webdev), but time warp is also very related to transactions and FRP in providing abstractions to deal with change in reactive programs.