Just guessing but they might be referring to their first datacenter in Fremont. No idea if it is even still around but their first DC was a hot mess. The newer one which is likely the one you are in was a night and day difference. The newer one had redundant power and networking and was built professionally. I say newer but this was a long time ago.
I've had servers in FMT1 since 2000. They had a series of power issues. Generators didn't start and everything died. Next time the power went out the generator started and the switch from the grid to the generator blew out the switching system (and killed one of my hard drives and who knows what else) IIRC. I'm pretty sure Linode moved to FMT2 because of this. There have been other problems but around 10 years ago they reached a point where the whole power backup system was new and they have only had one outage that I can remember since then.
We colocated in both Fremont DCs for about 10 years. Their newer one had 2 power outages within a couple months when we were there (I think this was in 2009 or 2008). I don't remember why exactly it happened, but I think for at least one they had redundant power disconnected for reasons. Other than that we had no issues though.
But it's been about 7 years since we've colocated our servers there.
All of my personal racks and (roughly) 1/5 of rsync.net have been inside the he.net core datacenter for 12 years.
I have never experienced a single power outage. Warm Springs datacenter.
Genuinely curious what you're talking about ?