The Gentoo package manager still has 0.10.2 as the most recent stable version. Getting a later version of the software on a gentoo setup requires explicitly telling the package manger to grab a later version. I don't know what percent of nodes are Gentoo 0.10.2, but I think it's evidence that 0.10 should not be considered 'unmaintained'. People who update their software regularly will be running 0.10 on Gentoo.
> many of whom have privately told me they are willing and able to
run an extra node or three (or a hundred-and-eleven) once there is a
final release.
I'm not clear on the utility of more nodes. Perhaps there is significant concern about SPV nodes getting enough bandwidth or the network struggling from the load? Generally though, I believe that when people talk about the deteriorating full node count they are talking about a reduction in decentralization. Full nodes are a weak indicator of how likely something like a change in consensus rules is to get caught, or how many people you would need to open communication with / extort in order to be able to force rules upon the network. Having a person spin up multiple nodes doesn't address either of those concerns, which in my understanding is what most people care about. My personal concern is with the percentage of the economy that is dependent on trusting the full nodes they are connected to, and the overall integrity of that trust. (IE how likely is it that my SPV node is going to lie to me about whether or not I've received a payment).
I will also point out that lots of people will promise things when they are seeking political change. I don't know what percentage of promised nodes would actually be spun up, but I'm guessing that it's going to be significantly less than 100%. I have similar fears for companies that claim they have tested their infrastructure for supporting 2MB blocks. Talk is cheap.