As in you can specify the time at which things execute and swap out the concurrency model at any time. This makes it perfect for testing: https://github.com/Reactive-Extensions/RxJS/blob/master/doc/...

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.

It's not. Virtual time can mean anything in this case as in not real time and it can be swapped out at any point.