Ok come to think about it, the last time I read about it was probably Judy Wood's book "Where did the towers go", but that's not the first time I read about these reports.

Searching just now I found this well researched page that goes over the same testimony she mentions in that book.

You're right about the blackout, since all mentions are from the day itself, oral history only, and never mentioned again in the MSM:

https://www.consensus911.org/point-wtc7-7/

On the issue of certainty, MSNBC reporter Ashleigh Banfield said early in the afternoon: “I’ve heard several reports from several different officers now that that is the building that is going to go down next,” with one of them saying “they’re just waiting for that to come down at this point.” [12] And indeed, many members of the Fire Department of New York are on record as having been confidently waiting for the building to come down. [13] For example:

Firefighter Thomas Donato said: “We were standing, waiting for seven to come down. We were there for quite a while, a couple hours.” [14]

Firefighter James Wallace said: “They were saying building seven was going to collapse, so we regrouped and went back to our rig. We went to building four or three; I don’t know. We were going to set up our tower ladder there. They said no good because building seven is coming down. We waited for building seven to come down.” [15]

Assistant Commissioner James Drury said: “I must have lingered there. There were hundreds of firefighters waiting to – they were waiting for 7 World Trade Center to come down.” [16]

Chief Thomas McCarthy said: “So when I get to the command post, they just had a flood of guys standing there. They were just waiting for 7 to come down.” [17]

Paramedic Steven Pilla said: “We walked back. We didn’t do [sic] any further because building number seven was coming down. That was another problem, to wait for building seven to come down.” [18]

Firefighter Vincent Massa, speaking of the firefighters waiting for WTC 7 to come down, has said: “The whole time while we were waiting – there were hours that went by.” [20]

Massa’s estimate is confirmed by a wider study of the FDNY oral histories. The study found that of 60 firefighters who mention predictions about the collapse of WTC 7, the times of these predictions can be determined in 33 cases: in 17 cases the predictions occurred within the two hours before collapse, while in the other 16 cases the predictions were made over two hours before collapse. In six cases the predictions were apparently made over four hours before collapse. [21]

Some reports indicate that the FDNY had been cleared from WTC 7 as early as 2 PM and had been told to abandon the building because it was doomed. [22] This forecast appears to have come from Mayor Giuliani’s Office of Emergency Management. [23]