I remember this at the time it happened. XD
To get into a bit more specifics on what people mentioned (I know this topic is an old now, this is to clarify things).
A reddit post
here explains it pretty well (and there's sources, so it isn't just an angry e-ranter).
The TL;DR though is that weren't just providing aid/assistance, there were actually trying to take down any video that was even slightly related to them.
In one case they tried to go after Ellen for showing an old phone to children.
In another case they took down a "Seniors React" show... And this was before Elders react even existed yet.
But as for their
falling subscriber count it seems to have died out around 13.5 Million like said above.
But that's still a good 500k subscribers lost in the span of a week (a drop that would likely be larger if not for the following damage control), which is really going to hurt them in regards to keeping sponsors.
Should also be noted though I actually talked with people who subscribed to the channel during the incident with the sole purpose of watching the shit storm... So take that into account with the 500k figure.
Granted, with the nature of YouTube Subscriptions that 500k or so will rise back up in no time at all.