In general I think the problems with this change have been slightly overstated. However, GP is correct.

The Fourth Amendment to the US Constitution provides in relevant part: > [N]o Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized.

A general warrant is one which does not "particularly describ[e] the place to be searched, and the persons or things to be seized".

The amended rule provides in relevant part > A magistrate judge [...] has authority to issue a warrant to use remote access to search electronic storage media [of which the location] has been concealed through technological means.

Now, one doesn't have to be a constitutional scholar to see that "the place to be searched" hasn't been interpreted recently (if ever) to mean "latitude and longitude". However, there's a valid concern that the inability to even place the "where" to a particular jurisdiction is a massive weakening of the requirement to "particularly describ[e]". It may indeed be so weak that the result can be fairly called a "general warrant". How could the warrant be written otherwise? What information could it contain? I speculate the "description" will amount, in practice, to "unknown hard drive in unknown location, possibly containing X contents". That is a general warrant, because no hard drive fails to meet those criteria.