Hello everyone.
I believe subj already described everything but will give you a little bit more context here.
One month ago, on Indexer Office Hours we discussed the problem, that sometimes small subgraphs have only one indexer. And it leads us to the possibility when queries couldn’t be served if this indexer broken\offline or just reallocating now. Another possibility is version changing, of course, The Graph has a really good mechanism for this kind of transition, but nobody uses it now (I don’t know why tbh).
There could be several possible solutions to solve all of these “issues”, but all of them require development, and I believe all core dev teams are already busy as hell 
So, I suggested a workaround for this, without development at all:
Big indexers can allocate 1 GRT to all small subgraphs automatically to guarantee query serving and support the network. Indexer community agreed that it could be a solution, it isn’t a perfect way, because it is based on goodwill, but it’s fast and doesn’t require development.
We decided to make it happen because we are strong believers in the Graph, we understand that software development resources should be spent really wise these days. And our suggestion doesn’t have any visible bad side effects.
That’s why I’m happy to introduce you: pillar-p2p-org, an indexer that will be operated by p2p.org as a non-profit initiative and will serve to the network as a backup for queries on those subgraphs where our main Indexer didn’t allocate.
Important info:
Do not delegate to it. It’s non-profit. You will not get any rewards from it, because we don’t plan to close allocations basically (maybe only for the tech reasons).